Kyousougiga Season 2 Episode 5 The Youthful Youngest Child's Problems and the Beginning and the End

Yakushimaru feels pent up over his past, even having an outburst at Koto. After getting some advice from Yakushimaru's girlfriend, Koto goes on a moped trip with him, explaining how A and Un are like the beginning and the end, reminding Yakushimaru of the words Myoe left him with. He then tells him that the black rabbit she is chasing is most likely his mother, offering to help her find it on the condition that once she does, she would kill him.