Maryan-senpai is up to no good. She gathered the To Heart 2 cast and played an RPG which players have to dive into. And dive into they did. Konomi becomes a witch and Tamaki becomes a warrior. Its up to you to recruit them into your team in the guild, get weapons from them and take them into the dungeon where the gods reside.
Admire the girls' new outfits and change their classes. Each of them specializes in their elements, such as magic and swordsmanship. Upgrade their skills as you proceed and line them up in a formation when you battle the monsters.
This is more than a cosplay party, dive into To Heart2 Dungeon Travelers.