[Machine Translation] -A new chapter has begun! This time it's an orienteering event! The rookie competition ended with a tumultuous ending. The winner was Otone Fujishiro, a mysterious beautiful girl who, like Erna, does not belong to any club. Erna immediately recruits Otone to establish her own club, but she seems to be a bit strange. On the other hand, Asuhi-kun, who missed the championship, seems to be depressed about something... Written by Last Note. The high-tension school xenobiotic battle story that is rapidly gaining popularity (!?!). The long-awaited fourth volume! This time, there is an orienteering event and a party after school! But Erna's new club is still in trouble... What's going to happen to the whole group? This is the fourth volume of the high-tension school xenobattle story!