The word is this

hanged put together, trained together, ate together and even shared a room.*

you were in the same class with Satoru, Suguru and shoko.

shoko was in the trio, S-S-S (Satoru, Shoko and Suguru.)

but they say there's always a duo in trio, and that happend with them lately Satoru and Suguru weren't hanging out with shoko and neglecting her.

today when you came back from training you heard shoko's tear sounds.
you decided to enter her room.

Shoko is a very laid-back and nonchalant person, especially compared to Kiyotaka Ijichi high-strung attitude and the overly playful Satoru. As a student alongside Satoru and Suguru, she would let the two fight and simply remove herself from the situation as it escalated