Haku Gaiden is a fan fiction sidestory that describes what happened after Haku's apparent death up until the current point in Shippuden. It is being authored by User:Mewshuji. It is divided into two tomes: the first describes everything up until Shippuden and the latter up until the end of the Kage Summit arc. It is still in the progress of being written.
Tome 1: Bonds
Chapter 0: Saying Goodbye
I have been here before,
But when or how I cannot tell
I have been here before,
But when or how I cannot tell:
I know the grass beyond the door,
The sweet keen smell,
The sighing sound, the lights around the shore.
You have been mine before,--
How long ago I may not know:
But just when at that swallow's soar
Your neck turn'd so,
Some veil did fall,-I knew it all of yore.
Has this been thus before?
And shall not thus time's eddying flight
Still with our lives our love restore
In death's despite,
And day and night yield one delight once more?
Haku's smooth hand patted the soil in front of him as his dainty lips finished the lullaby. "... Sleep... Well, Lord Zabuza," he whispered. Haku had indeed survived that day many months ago... But why he could not fathom. All he remembered was giving his life for Zabuza... Then waking up six feet underground. He was then dug out by a group of passing warrior monks who sensed his chakra. He was taken care of by them. But, the wound was incredibly infected- while a lot of it had been charred by Kakashi's Raikiri, a few bits were left intact and thusly infected by several ground-borne things. It had taken him a full year to recover. In that time, he had been taught things about life that were less violent- math, sciences, arts... He enjoyed those much more. But deep inside he knew he was a ninja. That's what Zabuza intended for him. So, the monks' leader, Saika, agreed to travel back to the Waves country so that Haku could say his final goodbyes to Zabuza and then go on his way.
Saika eyed his young companion. "You really cared about him, didn't you Haku?" the battered warrior monk asked, leaning against a tree. Haku looked to Saika and nodded. "What was he to ya anyway? A teacher? Father figure? Master?"
"All of those I suppose... And more. So much more... Like I said, he... He was the first person to ever treat me like I was important since..." Haku trailed off, bad memories coming back. The older man approached Haku and placed a hand on his shoulder. "Well, you know."
"Right, right." He smiled. "... You sure you gotta go kid?" he asked Haku, as the young man stood and began to walk off. Haku stopped after a few seconds and turned to Saika with a smile.
"Yes. Thank you for all of your assistance, Lord Saika but... I must continue on. I must do what Lord Zabuza would wish for me... Now that I cannot be his tool, I must find out what that is." Saika grimaced slightly, but that soon turned into a smirk.
"Well kid... This is goodbye then." He pointed his fingers at Haku like a gun. "Stay gold."
"You too, Saika." Haku turned away and walked into the mists of the Wave Country. A small rain began. The grizzled man chuckled and said, "Bang..." He lowered his hand and walked in the other direction, going back to his group's current camp.