The anime adapted from the manga remake version of the Korean webtoon "A Simple Thinking about Bloodtypes" involving the faceless and nameless characters of four different blood types to discuss about popular anthropomorphized blood types (the stereotypes about the blood types) in Japan and Korea.

When Sanpeita Kobayashi was a child, his lovely friend had to move away, but she vowed that in ten years, they would meet again—as husband and wife. Ten years later, Sanpeita is a high school student, but he hasn't forgotten the feelings they shared. Sanpeita awakes from a dream about his last day with her, only to have his morning interrupted. A weird robot girl is battling other robots in his bedroom, claiming to be his wife. The robot's pilot looks like none other than Sanpeita's long-lost, childhood friend. But who is she really? Why did she have to leave? And what does she have to do with the Mishima Electronics Corporation?

Transferring the human consciousness into a robotic "I-Machine" is now a reality thanks to the discovery of a valuable ore called "orichalt." However, there is the possibility of the consciousness failing to return to the host's body, rendering them stuck inside their new metallic frame for good. Such is the situation of members of the Excavate Company, a reckless band of I-Machine miners led by the notorious Grayman that aims to gather orichalt for profit. During a mining incursion, the group rescues Maya Mikuri, a student who was abandoned by her crew. Accused of stealing classified information on orichalt by her former colleagues, she joins the Excavate Company in hopes of clearing her name. They then begin an adventure that will change their lives—including that of Ido, an ace member of the group with no memory of his past. For the first time, Ido might have the chance to rediscover his true identity. [Written by MAL Rewrite]

Hikari is a young school girl who dreams of becoming a great champion in the sport of rhythmic gymnastics like her idol, Diliana Gueorguiva. Despite all her setbacks while performing, she works hard and with the help and support of Takaaki Oiishi (the best male gymnast of her school) soon becomes a member of the rhythmic gymnastics team in her school. She develops feelings for Oiishi, but she is not the only one—Hazuki Shiina, the best gymnast in the entire school, also has feelings for Oiishi. Soon a friendship between Hikari and Shiina develops, but also a rivalry as well in the sport and for the love of Oiishi. Hikari is also torn between her feelings for Oiishi and her conflicting feelings for Mao Natsukawa, an old childhood friend, who is also the lead singer of the band called Mr. D. He composes the music she uses while performing, and has been developing feelings for her since childhood.