When you think about it, one HAS to wonder if there's some sort of hidden message when you receive the same gift all the time. Especially in case of... uncommon items.
When you play game, you have also so called freetime parts, when you as Naegi can try to make bonds with other persons. By talking with them, but even more importantly by giving them presents. There is ca one hundred items you can draw in dangaronpa gachapon machine. Depending of target and his/her preferences each of items can make a perfect, good, passable, unwanted or disgusting present you can give. Of course if you want to make friends (and do it fast...) you want to give only perfect ones each time. For most characters, there is few perfects you can give them. For example Yamada will become your otaku bro for live for anime figurine or mega-super-duper-juicy video game compendium. The sporty girl Asahina will ask you if you have a girlfriend after you give her a swim suit, sports watch and/or... donuts. For Sayaka a classic approach with bouquet of flowers or single rose encased in tube is preffered. And so on.
tldr; I'm not absolutely sure (as I didn't have enough patience to check all 100 items) but apparently, there is only one gift which makes Ceres swoon... :)
