Senran Kagura: Estival Versus – Festival Eve Full of Swimsuits (also known as Senran Kagura Estival Versus: Shoujo-tachi no Sentaku) is an Original Video Animation that was released on March 26, 2015 alongside the deluxe set of Senran Kagura: Estival Versus.
It was one episode that was thirty minutes long.
All the girls from Gessen Girls' Academy, Hanzō National Academy, Homura's Crimson Squad and Hebijo Clandestine Girls' Academy arrive at a spa resort. While calling upon a temporary truce, a sour quarrel ensues over a trivial matter, so they settle it with a water showdown, ancient shinobi style!!
- Yumi and Yozakura are training in the snow. After defeating Yozakura, Yumi mentions a premonition of a great battle that she had.
- Upon returning to Gessen Academy, Minori opens a letter and finds free invites to a new spa. Everyone but Yumi wants to go, however Yumi ends up losing the ensuing "boob rock-paper-scissors" match to Shiki so they decide to go.
- Homura's Crimson Squad are walking down the street, hungry when they decide to spend the last of their money on a meat bun to share. Seeing they are down on their luck, the vendor also gives them a free raffle ticket, and they end up winning free tickets to the spa.
- Miyabi and Imu are looking over the reconstruction of Hebijo Clandestine Girls' Academy, when Ryōbi and Ryōna show up complaining that Murasaki hasn't been around since she got a new game console and they need to lure her out of her room.
- Ryōna reveals she has free tickets to the spa. When questioned how she got them, she answers "shopping" which turns out to be crawling around the market streets like a dog and having people throw her treats.
- Rin encourages the group to go, as Hebijo Academy won't be completed for a while, so they go and drag Murasaki out of her room, not even giving her a chance to save her game.
- When the groups arrive at the spa, they find the Hanzō National Academy girls are already there. Everyone decides to call a truce and have fun.
- However, the peace is broken when Homura calls Miyabi an old lady who likes to pretend she's still in high school. Instead of letting a fight break out in the resort, Yumi suggests they settle it with a water cavalry battle.
- Yomi has eaten too much of the free food and cannot participate. Homura asks Haruka if she has anything to help with that and Haruka goes through her bag. She finds a paralyzing drug, one to make you dance the samba, and an experimental one to make things grow larger, but none of them would help the current situation. She also has a seed that she says will grow into a wooden puppet, but it takes too long to grow to be useful right now. As such, Crimson Squad is not able to participate in the cavalry battle.
- During the cavalry battle, Murakumo's mask is knocked off, and when she can't find it in the water she decides to take off her top and cover her face with that instead.
- Ultimately, Yumi, Miyabi, and Asuka all remove each other's headbands at the same time, resulting in a draw. Unable to accept a draw, Yumi wants to keep going even if it means stripping your opponent naked. The others are not as into the idea.
- Suddenly everyone senses a presence. Asuka notes that it's like her grandfather, but "darker."
- Sayuri and the Mikagura Sisters are in the Forest of Requiem around the bonfire where they would eventually summon Ryōki. Sayuri is amused they were able to detect her and decides to spice things up. She sends a large group of Kuroku enemies to the spa. The girls summon their weapons and begin to fight back.
- Minori attempts to transform, but after pulling out her Scroll she discovers that something is blocking them all from being able to perform a Shinobi Transformation.
- Backed into a corner, the girls aren't sure what to do until Rin and Daidōji appear in a quick cameo to give them some words of encouragement.
- The girls take it to heart and activate Super Frantic Mode, becoming completely naked but gaining incredible speed and power.
- Ryōna was tired and didn't go Super Frantic with the others. Seeing Haruka's bag, she decides to have something to drink. Naturally, she ends up drinking the experimental drug to make things larger. Ryōna begins to happily smash Kuroku shinobi as she pretends to be a kaiju.
- Haruka suggests that they need to all fight her to make her sweat out the drug. Ryōna greatly enjoys this, likening it to being pricked by needles all over. Eventually she begins to glow and then there is a giant explosion.
- In the aftermath of the explosion, Ryōna has returned to normal size and the Kuroko are all gone.
- Asuka asks Yumi if this was the big battle her premonition warned her about, but Yumi says it wasn't anything this ridiculous.
- The girls all head their separate ways, saying they all had fun regardless.
- Senran Kagura: Estival Versus contain a Special Mission directly referencing (and advertising) this OVA. Though the trailer shown in the game is censored, the actual anime is not.
- This was the first time the Gessen Girls were shown to settle disagreements among themselves with a game of "boob rock-paper-scissors," which they would be shown doing again during the anime Senran Kagura: Shinovi Master -Tokyo Yōma-hen-. The other girls insist it was how Kurokage taught them to settle disputes though Yumi claims she doesn't remember that.
- Despite having retired from teaching at Hebijo Academy in one of the routes in Senran Kagura: Shinovi Versus, Rin is still shown to be a teacher there in this OVA.
- The Hanzō Academy girls wear their winter school uniforms when not wearing their swimsuits in this OVA.
- Haruka apparently finished recreating the Samba Drug she was trying to recreate during Senran Kagura: Bon Appétit.
- Instead of her usual giant shurikens, Murasaki is shown using a giant battle axe.
- Despite Shinobi Transformation having apparently been blocked, Daidōji has her post-transformation hair during her brief cameo. She may have transformed before arriving or is strong enough to override the block, however.
- This was the first time Ryōna became giant, something which she remarks a few times that she wants to do again, and actually succeeds in doing during Senran Kagura: Peach Beach Splash.
- This is the first (and so far only) appearance of Super Frantic Mode, a stronger form of Frantic that even destroys your underwear/swimsuit in exchange for more power.
- Ryōki is the only playable character from Estival Versus (not counting downloadable content) to not make an appearance in this prequel OVA, as she had not been resurrected yet.