Kanshakudama no Yuutsu

From Anime News Network: This is a two-part manga that was printed with three other short stories together in one book. The tankoubon itself shares the title of this story, Firecracker is Melancholy. Story 1) Kanshakudama no Yuutsu: Kajika is a female ninja and her parents were murdered by the rival ninja family Hayato when she was a little girl. Now, she lives with her grandfather. She falls in love with her senpai named Fujisaki. But he thinks that Kajika is too male. And Kajika's childhood friend Yuga has a problem with Fujisaki-senpai! When Fujisaki wants to date Kajika, she discovers something that is really shocking and surprising for her... Story 2) Kanshakudama no Yuutsu-Kimi ga inakucha (without You): Yuga can't go home with Kajika because he has some meetings with the SMV. He goes to the meetings with Fujisaki-san, the sister of Fujisaki-senpai, who fell in love with Kajika because she gave him freedom and mercy. Kajika is sad because she thinks that Yuga loves Fujiy