Keiichi Wakaouji
protector

Wakaouji is Mitsuki's private doctor, he visits her house of a regular basis to make sure she isn't straining her voice too much. Unlike Mitsuki's grandmother, Wakaouji is very caring and understanding of Mitsuki's position and dreams. Most of the time he is willing to do everything in his power to protect and make Mitsuki happy, however the only thing he doesn't approve of her her singing. He realises that singing will only make Mitsuki's cancer worse, hence he never accepts it.

He is also a close family friends, particularly toward's Mitsuki's father which is probably why he often treats Mitsuki like his own daughter. Mitsuki's father and Wakaouji used to be in the same band ROUTE:L, along with Takuto's former self. He was the one who tried to save Takuto's vocal but was unable to.