Junpei is depressed, he was hurt by Yua, his parents abandoned him, his grandparent is forcing him to a marriage meeting, he doesn't have the courage to tell Yui how he feels about her, and he feels useless because Mai was able to do everything he couldn't help with for the school festival, and he can't stand to be around his classmates because, he didn't help, but they treated him as if it didn't matter that he didn't do anything. Junpei's low self-esteem is adding to his undeveloped emotional maturity and indecision it's causing him not to be able to stand up and make decisions for himself and he has no one to rely on since Yui has drifted away a little bit, the stress is making him sick, Thanks for the update.