An OVA that will be bundled with the seventh volume of the Shinmai Maou no Testament manga, to be released January 2016.

The infamous Shounen Bat (Lil' Slugger) is terrorizing the residents of Musashino City. Flying around on his rollerblades and beating people down with a golden baseball bat, the assailant seems impossible to catch—much less understand. His first victim, the well-known yet timid character designer Tsukiko Sagi, is suspected of orchestrating the attacks. Believed only by her anthropomorphic pink stuffed animal, Maromi, Tsukiko is just one of Shounen Bat's many victims. As Shounen Bat continues his relentless assault on the town, detectives Keiichi Ikari and Mitsuhiro Maniwa begin to investigate the identity of the attacker. However, more and more people fall victim to the notorious golden bat, and news of the assailant begins circulating around the town. Paranoia starts to set in as chilling rumors spread amongst adults and children alike. Will the two detectives be able to unravel the truth behind Shounen Bat, or will the paranoia get to them first? [Written by MAL Rewrite]

Satou Matsuzaka is a beautiful high schooler who has a reputation for being permissive with men. However, a chance encounter with a young girl named Shio Koube makes Satou realize that this is her first and only true feeling of love. Telling others that she lives with her aunt, Satou secretly shares an apartment with Shio. Despite her innocent appearance, Satou is willing to do anything to protect her beloved, resorting to desperate measures to ensure that their "happy sugar life" remains intact. [Written by MAL Rewrite]

On a new day in the Kanto region, Satoshi gets invited by Professor Yukinari Ookido over to Professor Sakuragi's lab-opening ceremony in Vermillion City. During the ceremonial speech, Professor Sakuragi receives an alert of a possibly rare Pokémon appearing in Vermillion City's harbor, leading Satoshi and the other trainers to rush to the area in hopes of finding the mysterious Pokémon. At the harbor, they find Lugia—a Legendary Pokémon—engaged in combat with other trainers. Noticing the other trainers' tactics, Satoshi has his partner, Pikachu, strike Lugia with a Thunderbolt attack. Unfazed, Lugia flees, but not before Satoshi determinedly leaps onto its back. To Satoshi's surprise, he meets another boy, Gou, who leapt onto Lugia's back as well. The two ride on Lugia's back as it brings them along on a bizarre adventure across the seas. As it lets the two back on the ground, Satoshi and Gou bid their farewells to Lugia and return to Sakuragi Institute. Impressed by Gou's findings and Satoshi's insight taken during their encounter, Sakuragi requests for the duo to be his new research partners. And so the duo's journey begins, traveling across multiple regions to meet many new Pokémon—including ones that have the ability to Gigantamax!