In The Heart of Kunoichi Tsubaki

The isolationist Akane Clan, composed of an all-girls body mainly consisting of young kunoichi in training, has a code to which they all must adhere: "As men are dangerous beings, interacting with them is forbidden." Kunoichi Tsubaki, the leader of the Dog Squad, is an excellent trainee with a promising future, but she has started to experience a strange feeling in her heart... whenever the subject of boys is brought up.