One dinner-table announcement from dad and every hallway in that Setagaya mansion turns into a minefield. This is Reiji Miyajima writing the thing Rent-a-Girlfriend never let him do: actual movement. Where Kazuya stalled for a hundred chapters, Arata gets the blood-relation rug pulled out in episode one and the five sisters have to decide, on screen, what they were really feeling this whole time. Yes, the archetypes are off the rack, tsundere, tomboy, otaku, imouto, unshakable onee-san, and yes, the pivot from sibling to suitor happens faster than any human brain works. But the animation actually holds up, the faces sell the moments the writing rushes, and the discomfort is the point rather than an accident. You will either drop it by episode three or defend it in a group chat at 2am. There is no third option.
Arata Shiunji lives under the same roof as five relentless sisters in their sprawling Tokyo mansion, constantly serving as their personal punching bag. He fantasizes about peace and quiet, about a life where he isn't the family's favorite target for schemes and teasing. Then his father drops a bombshell: Arata isn't actually their biological brother. The revelation should liberate him. Instead, it complicates everything. Now that the biological bonds are severed, what exactly holds this chaotic household together? Are they still a family if blood doesn't connect them? The sisters begin to act differently around him, and Arata finds himself questioning whether distance is really what he wanted after all. What unfolds is a comedy that balances genuine moments of connection with the hilarious dysfunction of a house full of people learning to redefine their relationships. Romance blooms in unexpected corners as feelings shift and reshape. The Shiunji household becomes less about biology and more about choice, proving that family isn't always something you're born into.