Still being re-editing...
The Romaji ninja clan was possibly started before 3rd Shinobi War, when an average jounin of Hidden in Grass, gone to the Country of Swamp and got 'dropped' into hidden and old underground tunnel (it got collapse during the 3rd Shinobi War), caused by Iwa nins), came upon an out-of-place greenish-black scroll with mudded kanji for 'reptiles' being stuck in dried mud column that was formed long ago. The jounin, Sunasso struggled to pulled it out of mud column and after 13 seconds, the reptile scroll was out. Sunasso jump out of underground tunnel and look for a shelter so he could examined the reptile scroll closely and to open it with caution (you never know that a scroll could be a boogey trap). Settling in no-named town, Sunasso examined it and found what it seem a 'direction' that said 'in order to open this scroll, the Reptiles Summons Scroll (summon scroll for ALL reptiles), the would-be summoners must bring lizard, turtle, snake, and crocodilian, and mix all their blood along with your blood to make this scroll recognize you and your descandants a summoners for reptiles'. Sunasso as the first summoner for reptiles had undergone a several tasks to fullfilled the requirements of each reptile-types in order as starting with turtles/tortoises, lizards/salmanders, snakes, and finally crocodilian. Each reptile summoning requires special different ending handseal (a special handseal that represent the type) and only turtles/tortoises required small amount of blood, while snakes (this was before Manda became Snake Boss) and crocodilians required good amount of chakra and little more blood. The Romaji Summons can be summon only by Sunasso's descandent (current Romaji clan summoners).
The Romaji clan used to be part of Hidden in Grass, resided in their own properties which was about half the size as the Hyuuga Clan Properties (lands, houses, etc.), lived there until the Iwa ninjas launched their attack on Hidden in Grass, initializing the 3rd Shinobi War. Not wanting to suffered the same fate as citizens and ninjas of Hidden in Grass, the Romaji clan fled with all their Romaji clan jutsu, including the most valuable and important scroll, the Reptiles Summons Scroll. When the 3rd Shinobi War was over, the Kusakage had declared the Romaji clan as desserters and an outlaws, placing the bounties on the Romaji AND their precious summon scroll. However, after weeks or so, the Kusakage along with his council was forced to declared 'their mistake' (announced that the Romaji clan is nonexisted) due to one man, Sarocha Romaji with help of his lizard (name unimportant) have what we would called the blackmails that could ruin the Hidden in Grass village's existance, since the Kusakage and his council have the records, including the dirtiest deeds and Sarocha Romaji somehow got his hands on it. Since then, the Elemental Countries have almost forgotten a existance of Romaji clan and the Romaji Summons Scroll. Until later after Narito Shippunden's timeline
NOTE:There is a separated summon scroll for each reptiles, in partically snakes and salmanders, as Oroochimaru had Snake Summon Scroll (later Anko was said to hold it) and Hanzo had Salmander Summon Scroll (nobody know what happen to salmander summon scroll, after Hanzo's death). The Romaji Summon Scroll does NOT affect a separate summon scroll for each reptile. Also human Romaji clan member will not be able to use sage mode and sage/nature chakra. Also dragons AND dinosaurs are NOT included in Reptiles Summons Scroll. For some strange reason chameleons are not included as one Romaji Reptile Council was heard muttering something about 'chameleons' and 'arrogance'.
Human Romaji Clan:
Is the clan of humans and ninja that specialized in reptiles summoning and Reptile-Style jutsu (including poison). In order to able to sign the Reptiles Summons Scroll, the person must be the first of his/her family, the scroll's contract with current/previous human Romaji clan must be 'invalid', meaning the last remaining member died with producing an offspring, otherwise the other person's clan will not able to sign the contract in Reptiles Summons Scroll.
For example, Hado heard about the summon scroll for all reptiles, somehow snuck in the current Romaji Clan (Sunasso's descandents), stole the scroll, and tried to sign his name with his blood in Reptiles Summons Scroll. But the scroll refused to accept his blood, because it already had a current Romaji Clan (Sunasso's descandents), unless if the current Romaji clan were to be 'extinct' or if the current Romaji clan broke one or two agreements in the contract. If Sunasso's descandents were said 'wipe-out' by disease, then Hado will able to sign his name in the Reptiles Summons Scroll, thus agreeing to change his current surname to 'Romaji' and to start the next Romaji Clan, providing if he had collect lizard/salmander, turtle/tortoise, snake, and crocodilian, and mix his blood onto the scroll. Meaning the scroll will not accept other human, who don't have Hado's blood in their vein, because of the agreement between the Reptiles, scroll, and Hado. (NOTE: Just because Hado sign his name does NOT mean his parent/siblings/cousins/relatives will able to summon reptiles. Only Hado and his descandents able to summon reptiles). This is just an example.
Their Daily Rountines
The human Romaji clan would care for their youngest generations until at age 5, where the parent or clan would train them in basic education, battle tactics, taijutsu, and chakra control and reserve excercises, seeing that all-reptiles summoning jutsu take a good amount of chakra (after all, it wouldn't be good idea after signing the summon contract and suddenly died from chakra exhuastion after ONE try in summoning). This training continue until age 14 or 15, where they would to prove that they're adult by summoning one or more reptile leaders (or boss) ,like the Uchiha children prove their maturity by doing Fire Release: Great Fireball, or at least to able to summon the adult size of 4 reptiles. NOTES: Most of the Romaji summoners specialized in reptiles summoning and taijutsu, while some Romaji summoners can also used water or earth jutsu as well as weapon-type(s) techniques. The strongest Romaji summoner that had ever grace the human and summon Romaji was Gilera-Sekira Romaji, who was, according to current Romaji clan, can summoned all four reptile boss with little struggle.
Tasks and Tests of each Reptile Leader:
Only first summoner had to fullfilled all the requirements, not just to able to summons all types of reptiles, but to make reptiles summons as a 'family' summon until the last of family/clan died without producing an offspring. The name, Romaji are actually a name and represent all reptiles, the reptiles give 'Romaji' if the person is the first of his/her family to summon the reptiles, after finding the Reptiles Summons Scroll. As far as anyone, including Sunasso concerned, Sunasso was the first NINJA Romaji summoner.
Turtles/Tortoise: The summoner must able to hold and to prevent turtle/tortoise egg from dropping it in any circumstances such as earthquake, itches, etc. before being allow to summon turtles/tortoises 'freely'. This is a test for would-be-summoner's abiltiy and strength.
Lizards/Salmanders: The summoner must able to catch and hold lizard/salmander for 10-20 minutes and it is no easy task as salmander/lizard is very slippery and fast on ground, before being allow to summon lizards/salmanders freely. This is a test for summoner's speed and intelligence (after all, summoner is allowed to use any stragety to catch lizard/salmander)
Snakes: The summoner must able to endure the weakest poison (in snakes standard) and to withstand pain. This is the test for strength of summoner's will and enderance. Like as 2 mentioned reptiles, the summoner will able to summon snakes 'freely' and requires no sacifice (again, this was before Manda became Snake Boss and we don't know for the fact that ALL snakes demand a sacifice).
Crocodilians: This is the most hardest of all reptiles tests as crocodilians are more battle summons with good offense and defense. The summoner must SURVIVE and not get hit by every single attacks from his/her crocodilian oppenent for 25-30 minutes. This is test for summoner's battle, strength, and instinct. If summoner manages to survive, not only being able to 'freely' summons crocodilians, but earned their respect. (Unless summoner does stupid thing such as summoning them for a ride, 'weak enemy', no reason, etc., they will eat the stupid summoner). NOTE: the Crocodilians test has between 74 to 80% chance of ending up dead as the Crocodilians take their task (not test) seriously.
NOTES: The Reptiles summons, like most of the summons, absolutely hate being summoned just to give their summoner a ride, even jumping over a volcano or crossing island (which at once there was unknown named Romaji summoner tried to get his giant-size lizard to get him across the lake, but he was 'accidently' got pushed into a lwater, before being eaten by wild man-eating fish) to another island. The reason why human Romaji clan doesn't complain is because it's in the contract between the Romaji Summons Scroll, the Romaji summoners, and the Romaji summons (reptiles). This is one of the 'risks' of being Romaji summoner. (Remember that Manda, after being summon by Kabuto, would killed Oroochimaru and Kabuto, if he had known weakness of Oroochimaru.)
Also, the beginner Romaji summoners doesn't alway started their first Reptile summon as Turtles/Tortoises, meaning they could start with lizards or snakes. The Crocodilians are usually the last Romaji summon to take the brutal test from them, which why turtles/tortoises are the first of the line as crocodilians being the last, lining up from 'easier' to 'hardest' difficulty.
Benefits after sucessfully pass all 4 tests:
Not only to able to summons all 4 reptiles, but each test come with each special jutsu called Reptile-Style, which involve in defense, offense, speed, body enchancement (not like Sage Mode), and combination attack/defanse with summon(s) such as performing Reptile-Style: Poison Steam with snake or lizard. The turtles/tortoises mostly involved in defense and sometime earth or water.
Lizards/salmanders involved in speed, offense, and sometime information-gathering (as some species of lizards/salmanders have sticky/webbed feet and can adapt some environment, except heavy cold environment, off course). Snake heavily involved in offense, assassination, and poison. And finally, crocodilians involved in well balanced offense and defense, and sometime body enchancement such as increasing density of summoner's skin (this is NOT crocodilian sage mode) or to able to breathe in freshwater (only, doesn't work in saltwater like an ocean).
Leaders and Councils of Reptiles Summons:
Each reptiles has their own leader and representive of their type (turtles/tortoises, lizards/salmanders, snakes, and crocodilians). Their leaders, together, are the council, meaning that they ruled all reptiles summons in similar manner as old royal rulers with government like King John(?) and the Paraliment. All 4 reptiles work together to 'manage' all reptiles. In ???'s time, the reptile leaders are Blackiron Shell, Grime-Away, Tyrant-Toxic (supposedly Manda's uncle of sort), and Moral-Crush. (Their Japanese name will be coming). Most of the time when all 4 reptile leaders are deciding on actions of their 'tribes' and their human Romaji summoners and what should be done, and sometimes they don't agreed each other and would end up snapping or challeging at each other. They also responsible on their summoners' marriage, for instance, if Dero Romaji wants to marry Kiwa Galiou. Then Dero would has to get permission from both human AND reptiles leaders, where human leader and depending how many types of reptiles he can summons would marry Dero to Kiwa. And Kiwa would had her surname changed to Semi-Romaji as recognization as spouse to Romaji summoner (this applied to out-of-Romaji man as well).
The Limits of Romaji Clan, the summoners and Reptile summons:
The limits/weaknesses of the Romaji summoners is that most of their clan techniques are limit to Reptile-Style jutsu (including summoning), few Earth and Water jutsu, few kenjutsu stytles, and few taijutsu styles. Because almost every Romaji summoners/members have a affinity for Earth, Water, or sometime both, the Lightning jutsu are the most effective against them (Romaji clanmembers and the summons) as they dealt more damage to them.
As for the Reptile summons, most of them aren't able to use ninjutsu, genjutsu (though a very few snakes have capabilities to use it, but in lesser extent), and depend on their sizes, shapes, and specialties (such as smaller sized summons like snakes and lizards are used as assassination and recon as 100 ft crocodile/turtle/snake/lizard are use to cause destruction or to battle against the enemy's giant size summon, like Toad/Tiger/Bear/etc.).
Although most Romaji summons can fight/travel on ocean water, the salt water seem to cause an irritating skin itch and would IMMEDIATELY dispel themselve if their summoner summon them to fight on or near the ocean. The ONLY Romaji summon that can handle the salt water is 'sea snakes' (not serpants).
Some Romaji Summons Have Their 'Unique' Appearance:
Like other summons, the Romaji summons are not without a few 'oddities', such 2 or 3 heads snake(as seen during the invasion of Konoha arc.), 2 heads turtle, 2 heads crocodiles, 5 legs lizard(that was suppose to be born as twin, but died after birth), 3 eyes alligator(later has 2 eyes, after her 'brutal' battle), albino snake, albino salmander, teethless caimen(who later got fake teeth implant and died after choking), oddly-slight-fur-that-strangely-look-like-a-beard tortoise(his nickname being 'the Gramp'), one-eye crocodile(who later went blind after his accident) and so on. As you can see, some of mentioned reptile 'oddities' died either from being birth or later. Reptile oddities are usually cause by 'DNA/egg problem' (birth complication) and it RARELY occur/appear.
List of Reptile-Style Jutsu:
Colorful Lizard/Salmander/Snake Replacement
Crocodile/Allegator out-of-freshwater(This is like crocodilian version of Wreck-A-Mole, only it used on water and it's offensive jutsu)
Swinging Shock Shell (in conjunction with trutle/tortoise, work like a wrecking ball)
Swamp-Pit of Hungry Crocodiles/Allegators/Snakes
Cave-Up Snapping Turtle Head
Crocodilian Jaw Wall Crush (the ONLY earth reptile-style of crocodilian)
Slime Path (sometime in conjunstion with lizard/salmander)
Sticky Slime Trap (same as above)
Wrapped Snake Shield (in conjunction with snake and ONLY defense reptile-style of snakes)
Unexpected-Knock-Out (in conjunction with lizards/salmanders/snakes, usually small-size or toddler-age)
Grub Dinner (not actually a jutsu, but techinique in which snakes/crocodilians eat summoner's enemy/enemies alive while summoner hold enemy(ies) in place)
Poison Steam (usually in conjunction with lizard/snake)
Bad-Air Breath (the least lethal of Reptile-Style jutsu and can be used without lizard/snake)