Kazuma Satou, former NEET and current reincarnated adventurer, finally returns home after the incident at the Crimson Demon village. He is joined by his ever-reliable companions: self-absorbed goddess Aqua, one-trick pony arch-wizard Megumin, and masochistic crusader Lalatina Ford "Darkness" Dustiness. Following their recent exploits, the party is one step closer to vanquishing the Demon King and his armies—a terrifying task that Kazuma is eager to ignore for as long as possible. Things, however, are not going as smoothly as the group would like; they are constantly racking up debt, getting sidetracked during missions, and falling into traps due to their recklessness and eccentricities. As the party struggles with their perennial issues, they receive an invitation from a princess interested in hearing tales of the group's "heroic" deeds. Darkness' pleas to refuse the invitation only fire the others up to accept it, marking the start of yet another uncanny adventure with unforeseen consequences.

The story takes place one year after the OVA. Because of the previous war, Kabucki-cho was devastated, and the owner abandoned his lingerie pub, "Pallion," and opened "New Papillion" in Akihabara. During the war, Tsubomi, and her colleagues Anne and Shizuku lost their memories, and they began new lives in Akihabara. On the other hand, the Susano, aliens who were invading the Earth, appeared. They turned a UMA (Unidentified Mysterious Animal) into a monster and make it raid on Akihabara. Rama the cat made Tsubomi and her buddies retrieve their memories, and let them fight against the monster as Lingerie Soldiers.

Based on a 1984 serial on the "Animevision" video magazine. The original material was compiled into this one-shot video.

Rentarou Aijou has it all: looks, intelligence, athletic skill, and popularity with peers and mentors alike. Unfortunately, none of these qualities help Rentarou with his love life. On the day of his middle school graduation, he is once again turned down by a girl he confesses to, earning his one-hundredth rejection in a row. Down on his luck, he goes to a matchmaking shrine and wishes to finally get a girlfriend in high school. When the god of the shrine suddenly appears before him, Rentarou is told he will meet an astronomical total of one hundred soulmates in high school. Though Rentarou initially does not take this foretelling seriously, his doubts disappear when, on the first day of school, he meets two of these soulmates—Hakari Hanazono and Karane Inda—who both confess to him. With fated encounters and love confessions galore, Rentarou's life is about to get a lot more exciting.