This is the best chapter so far.
Momo totally destroyed herself, Riko had no bad intentions, she genuinely recommended her the best present after Momo bought her something worth 7800 yen, and yet Momo's pride and being unable to trust other people completely blinded her, so Riko went and did the prince act herself and worked perfectly, Momo has no one to blame but herself.
Then the best part, Shamiko treasures Momo's gift more than everyone else's to the point she puts it alongside her ancestor, but Momo is so dense she can't even notice it, she's just angry Shamiko isn't using it, so even though she actually earned some points with Shamiko she ended up thinking she lost. Just pure perfection, it'll be hard for another chapter to top this.