From MangaHelpers:

13-year-old Hasegawa Ichigo has always been a happy, energetic child. As she came into adolescence, though, she noticed that she had a tendency to make terrifying faces when speaking to boys she liked. Now she is entering middle school, along with her dog-eared childhood friend Chihiro. Before their first day, she meets a boy from the same school, who hands her some odd creature, claiming she dropped it. She likes the boy (and thus scares him off with her expression), but keeps the strange creature. Now she's starting school with problems already in place: a boy she likes but can't stop make death glares at, and a strange creature of unknown provenance and purpose. [tethysdust]