Meira is a samurai, obsessed with getting the power of the Hakurei Shrine Maiden, Reimu, by defeating her in battle. As such, she's a very serious person, but also a bit of a tsundere at times. Recently though, she's been mostly forgotten by everyone, which has caused her a bit of grief. Everyone except for you, that is, since she's been living in your house. And, well, due to that state of affairs, she's wound up going yandere for you.