Minna Atsumare! Falcom Gakuen

The warriors who have been warped by the rampaging power of "justice" have been summoned into the world of Xanadu. It's up to Dark Fakt, a former villain, and principal Lappi to re-educate these students.
(Synopsis courtesy of ANN)

Unknown number of 3-minute episodes; based on an ongoing Seinen manga with 2+ volumes released in the Falcom Magazine.

"みんな" ("minna") = "all, everyone"; "集まれ" ("atsumare") = imperative of "to gather".
"ファルコム" ("fa-ru-co-mu" = "falcom"), being written in katakana, isn't a Japanese word but refers to the name of the Japanese game company ↗Nihon Falcom whose 30th anniversary is celebrated by the manga, and various characters from Nihon Falcom's video game franchises appear in the series.
"学園" ("gakuen") = "college, academy".