Yukino and Kanade Sakurai are twin sisters who live in a high school dorm together. Despite the fact that they are twins, they act romantically toward each other, holding hands and going on dates. Kanade notices Yukino with a new girl, Sakuya Kamiyama, one day. Kanade assumes they are dating after noticing how much time they spend together, and she begins to distance herself from her sister. Yukino immediately notices and begs Kanade not to leave. Sakuya, in reality, has only been seeking advice about Kanade, revealing her obsessive love. What will the outcome of this love triangle be?