HELP!!

There's this manga that I want read again but I can't remember the title. The couple have a huge height difference and the shorter one is the seme. I remember the seme's characteristic as a yandere and a cutie. And the always wear hair ties and specifically a cute hair tie that the uke gave to the seme I guess?? Meanwhile the uke has a delinquent image but I can't remember if he is actually a delinquent. As for the plot I can't really remember much but at some point the seme stopped being cute? Like he turned more into a flowery-prince-popular-boy type?? I dunno but he certainly stopped wearing the hair tie. It's like the hair tie is real important but I can't remember if it's a hair tie or hair pin.

Anyways, please help me find this manga.
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