I, Konoha's Sage of Life

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!"