Bundled with manga's tenth and eleventh volume.

Yuna and Akari are two high school girls with very different views on love: Yuna dreams about romance through rose-coloured glasses, while Akari is down-to-earth and practical. Meanwhile, high school boys Kazuomi and Rio also have different views on love: Kazuomi is an airhead who can't grasp the concept of love, while Rio grabs onto any confession as an opportunity—so long as the girl looks cute. Will these four classmates end up leading a youthful romance that meets their expectations? (Source: MAL News)

As Jun Sakurada fights and lives alongside the Rozen Maidens, special lifelike dolls made to battle each other, he enjoys a rare break in which he is told a story during the events of Rozen Maiden: Träumend. When Jun buys a brooch as a present for Shinku, the fifth doll, she refuses to accept it at any cost. Souseiseki, the fourth doll, then recounts the story of how Shinku and the first doll, Suigintou, first met. This tale tells of the cruel and heartbreaking circumstances surrounding Suigintou's birth, and how the many misunderstandings between her and Shinku shaped their longstanding rivalry fueled by Suigintou's unfettered hate towards Shinku. The stage is set in Rozen Maiden: Ouvertüre in 19th century London as the story delves into the past of these one-time friends and the secrets that they hold. [Written by MAL Rewrite]

Upon hearing news that his mother was on verge of death, Haru Kaidou—the eldest son of the family—flies all the way to Canada. The moment he arrives, he learns that not only did his mother fool him, but he is also supposed to take care of his adoptive brother, Ren Kaidou, an antisocial kid who feels more comfortable around dogs than people. Due to his new brother's distrustful nature, Haru initially has a hard time reaching out to Ren but their relationship eventually grows. He makes a promise to Ren: they will live together in Japan after Haru graduates from high school. However, due to an unfortunate accident, Haru loses all memories of the summer they spent together, including the promise he made. Five years later, expecting Haru to keep his promise, Ren arrives in Tokyo; but to Haru, Ren is just a random boy claiming to be his brother. [Written by MAL Rewrite]