Ashita No Tamago
Other titles :
あしたのタマゴ, Ashitama, Tomorrow's Egg
Author(s) :Tachibana Kaimu
Makoto Katsuya, bumps into his grandson, Yuusuke Katsuya who came from the future Tokyo by a time machine. Yuusuke explains to Makoto and the childhood friend of Makoto, Momoka Shiroishi that he needs help to save his father who was arrested on false charges.