To Love-Ru Trouble Darkness: Battle Ecstasy

One day, when Rito was in his house, he suddenly became dizzy, and when he came to his senses, he was in a strange world. Momo suddenly appears, and from her he hears that he is imprisoned in a strange world and that Lala has been whisked away to a mystery dungeon. So Rito decides to head out and rescue Lala from the dungeon she is held prison in.