Aiko Kido

Aiko is a very serious and studious child, despite his outgoing and hippy mother, Nana Terrano. Ever since he was a child, he'd been told that his father was her old boyfriend, Shinjiro, who died of lung cancer just before he was born. However, the truth is that Joe slept with Nana during a brief breakup. Aiko has alwyas known, however, even before being told directly, since he found an image of his sonogram in one of Joe's photo albums.

In 2020, his mother goes on a date with a man she just met and never returns. Scared, Aiko runs to Joe's apartment where they wait together. Unfortunately, instead of coming back, Ken informs Joe that Nana has been murdered. Aiko is formally placed in Joe's care.

In 2021, Joe begins dating a man named Tomaru Itsuwari. Aiko is scared of Tomaru and the night they're introduced to each other, Joe tried to break up with Tomaru and ended up posioned. Aiko called an ambulance to save Joe and that was when Joe realized he needed to protect his son, by killing Tomaru in self-dfense.

In 2025, Joe invites Matt to live with him after the man's suicide attempt. Though wary of a new man in their lives, Aiko can see that Matt makes Joe happy and Aiko quickly warms to him, giving him the name of "Yamapapa".

Aiko plays the saxophone in his school band and wishes he could have lived with his mother just a bit longer.

2013: born in March

2020: Nana is murdered, moves in with Joe

2021: Tomaru begins stalking Joe

2022: Joe kills Tomaru in self-defense

2025: Matt moves in with Joe