Mahou Sensei Negima!: Mou Hitotsu no Sekai
Japanese title: 魔法先生ネギま! ~もうひとつの世界~
Type: OVA
Episodes: 4
Source: Manga
Genres: Action, Adventure, Supernatural, Ecchi
Studios: Shaft, Studio Pastoral
Duration: 29 min per ep
Rating: PG-13 - Teens 13 or older

This is a series of OVAs covering some of the Magic World manga arc by Ken Akamatsu, starting with chapters 184 through 188.