Diane Scott was the only friend Katherine Greene had after the Doctor left. They traveled the earth together, investigating possible alien activity. But, after a glitch with an old Vortex manipulator, Diane found herself separated from Katherine, and trapped in the year 200,000, aboard Satellite Five, a futuristic news station. But this is not the end of her story...oh no. It's only the beginning.
She knows as soon as she see's the man that he's the Doctor. Just as Katherine had told her, you'd just know that he was different just by looking at him. You lose one Time Lord, you get another. Along the way, she meets Rose Tyler, and Captain Jack Harkness, but her life is about to change forever...literally forever.
After Rose absorbs the heart of the TARDIS, she ends up accidentally leaving Jack and herself with the ability to never die. And, being left behind by the Doctor and Rose, the two are forced to live through the centuries, until they find themselves in modern day Cardiff, co-leading the new and improved Torchwood.
Kanda Kyoichi transmigrated to Konoha and became a temporary instructor at the Ninja Academy. Fortunately, he awakened the Mentor System.
By teaching others, he could earn rewards.
Thus began Kyoichi's career as a "teacher" in the ninja world.
Shisui: "Sensei's unique interpretation of the Will of Fire has given the Uchiha Clan a true sense of direction!"
Asuma: "The essence of the jade lies in protecting the people, with the advanced leading the way for the less experienced. Only then can Konoha become stronger!"
Kakashi: "He's my life mentor. He transformed Konoha!"
...
Years later, in the memoirs of Kyoichi, now the Hokage, he wrote:
"I honestly just wanted to be a life mentor!"