Four variables, two asymptotes | SHSE AU

Sieun graduated and decided to take a sabbatical year before going to university and, in the mean time, he works in a library while also preparing for the uni test.
At his work place, he got to meet Juntae and also Suho.
Gotak and Seongje will join the trio at some point.
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- Please, sign your entrance at the library with your library card. If you do not have one, I will help you create it. - Sieun didn't smile, just stated the facts with a quite dry tone but the young man in front of him smiled brightly, adjusted his glasses and took out a card with the logo of the place.

- Ah, thank you, thank you... -, he leaned forward ever so slightly to read the name on his jacket, - ... Yeon Sieun-ssi. I'm a regular here so I know my way around but thank you anyway!