Sorry again, i'm looking for a fanfiction but i forgot the title. 

I think it is still ongoing but it's a really good read for me.

Storyline goes like this :

Tiffany has a crush on Taeyeon and is sort of finding some way on how to get Taeyeon's attention. Taeyeon knows that Tiffany likes her and they are graduating soon. They are assigned to do some dance performance and during practice Tiffany keeps on staring on Taeyeon. One time Tiff's ankle got injured and both Tae's and Tiff's friends all (Yuri acted like she didnt know how to go to the Pharmacy, so all of them went  together without TaeNy) went out trying to look for Pharmacy.

Tiff's friends ; Yuri / Hyoyeon

Tae's friends : Sunny / Seo Hyun / ... ???

Tiff's report went missing and was told she probably can't graduate. she has to do her report in a day, Tae patiently accompany her in the library. Tae called Sooyoung to buy foods but Sooyoung misheard it and bout T-shirt and a bag hahahahah

I think thats all that I remembered in details haha