Day 32 in the Keisuke Route, after Shoichi says 'Yessir' in response to the unreliable topic relating to MC/Yuushi, Saya and Keisuke come in, but only Keisuke is seen, Saya's sprite is noticeably missing. Even though Saya goes through her usual 'Osu!' dialogue among other things, she only reappears once Yuushi says 'There you guys are. Would you go ahead and tell these two that I'm not unreliable'. I don't know if this is an actual bug but I'm assuming it is one since she kinda just randomly appears and it makes no excuse such as her being on the ground/out of view.