Senran Kagura: Ninja Flash

Asuka, Ikaruga, Katsuragi, Yagyu and Hibari are five school girls who secretly train in the ninja arts. As they are sent by their mentor, Kiriya, to handle some delinquents in town, Asuka meets a girl named Homura and helps guide her through town, unaware that she is secretly an enemy shinobi. Meanwhile, the others encounter the delinquents, who are soon revealed to be wooden puppets controlled by an enemy shinobi. As the girls manage to beat the puppets, Asuka remains blissfully unaware of Homura's true alliance.

As the girls train in summoning animal spirits, Asuka is the only one having trouble summoning hers. Her grandfather, the legendary shinobi Hanzou, comes to visit and informs her that their family's spirit is the tree frog, which Asuka is afraid of. As Asuka attempts to get used to frogs, Hanzou informs Kiriya that the evil Serpent Academy for Girls is behind the puppet attack. On their way home, Asuka and Ikaruga are attacked by one of the enemy shinobi, Yomi.

Yomi engages Ikaruga in battle and overwhelms her with her array of weapons before taking her leave. Later, Ikaruga is informed that her brother, Murasame, who she replaced to become the shinobi successor of her family, has gone missing. Later that night, Ikaruga encounters Murasame in her room stealing her sword, Hien, but she manages to send him packing easily enough. After being ejected from the household, Murasame is met by Hanzou, who reminds him that being a shinobi isn't the only way of life. After receiving some advice from Hanzou, Ikaruga decides to start giving Asuka summoning lessons, managing to help her get over her fear of frogs and learn to use her summoning art.