Anthoniko (あんそに子 Ansoniko?) is Mei's teddy bear keychain.
It is a keychain that originally belonged to Yuzu, but she later gave it to Mei.
Role in the Series
As Yuzu runs away from Himeko, she accidently drops Anthoniko, causing him to tear a bit. Mei finding him, picks him up and tells Yuzu to wait. Distracted by this, Yuzu hits the wall, being sent to the infirmary for a bruised forehead. Mei tries to fix Anthoniko, but it is revealed that she is not good at sewing, so instead Yuzu fixes him as Mei leaves. Yuzu says Anthoniko said "thank you". Being touched by that, Yuzu decides to let Mei have him.
When Yuzu finally decides to confront Mei about their feelings for each other, she asks Mei to kiss her as proof that Mei's feeling for her are the same as hers. Mei was hesitant at first but used Anthoniko to kiss her first. Yuzu thanks her but says she wants a kiss from Mei too. After saying that, Yuzu kissed her.