Manga by author Meguro Amu - Status ongoing

From Leaping into Puddles:Clumsily, he panicked and hid the flower bouquet behind his back...This is what happens one day when ordinary girl Kogure Nao is summoned by the scary-looking Onigase-kun. However, she is shocked when he says to her: "Please date me before you marry me!" Nao is too shocked and terrified to say no... what will come of their relationship?

The manga centers on Sui, a girl in her third year of junior high. She doesn't really get along with her older sister's boyfriend, Midori-kun, since he always treats her like a kid and makes fun of her. But Midori-kun is suddenly asked to be Sui's home tutor.