Magical Girl Raising Project, Vol. 14 (light novel)

An experiment gone wrong leads to the death of a famous mage, and thepassing of
this illustrious individual sends the Magical Kingdom intomourning. Then, a few
months later, the deceased mage-s relationsreceive letters from his proxy regarding
the inheritance of his estate,inviting them to a tiny uninhabited island the mage had
used as a getawaycottage/research lab. When Mana gets one of these letters,she-s
skeptical, but after careful consideration, she contacts twomagical-girl friends to
accompany her there...