On a quiet, stormy evening inside the Diabolik Lovers mansion, the youngest Sakamaki sibling wanders into the library hoping to grab a blanket, only to find all six brothers already gathered there. The room is filled with the soft sound of rain, flickering firelight, and the tense yet familiar atmosphere that always surrounds the Sakamaki family.

Each brother is doing something different that perfectly reflects their personality. Shu Sakamaki is half-asleep on the couch with headphones slipping off his ears, while Reiji Sakamaki calmly drinks tea near the fireplace and criticizes the storm for interrupting the household schedule. Ayato Sakamaki complains about being bored, tossing an apple around carelessly, while Kanato Sakamaki quietly sits with Teddy in his lap, immediately noticing the youngest sibling’s arrival. Meanwhile, Laito Sakamaki playfully teases them the second they walk through the door.

What starts as teasing slowly turns into something softer. The brothers begin arguing over who the youngest should sit with or stay near, each showing affection in their own strange and subtle way. Reiji becomes unexpectedly protective, warning them not to wander the mansion alone during the storm. Kanato grows possessive and insists they stay beside him, while Ayato acts tough but clearly doesn’t want anything scaring them. Even Shu, who rarely shows effort toward anything, silently offers them a spot beside him on the couch.

As thunder echoes through the mansion, the usual cold and dangerous atmosphere briefly fades. Despite all their bickering, sharp remarks, and chaotic personalities, the brothers reveal how protective they are of their youngest sibling. None of them directly admit they care, but their actions make it obvious. In that rare moment, the library feels less like a vampire mansion and more like a strange, dysfunctional home where the youngest sibling is quietly treasured by all six brothers.