Iroha, who has been living with her mother, now has a sister named Rika due to her mother's remarriage. Rika is close in age. Iroha, perhaps because she grew up with her father, hit it off with Rika's straightforward personality. Since realizing she was a lesbian during her school days, Rika knew she was a lesbian with girlfriends and lovers. Secretly aiming for Iroha, Rika finally...!
