Isekai Mahou wa Okureteru!  

The Different World Magic is too Behind!, 異世界魔法は遅れてる！, The Magic in this Other World is Too Far Behind!, 異世界魔法は遅れてる!

Felmenia Stingray was an exceptionally skilled magician in the Astel Kingdom. She gained prominence after mastering white fire magic, which had immense power to destroy anything. However, the kingdom faced imminent danger from the Demon King. The court's magicians summoned heroes through a ritual, producing two young individuals - a boy and a girl. While the girl was willing to fight against the Demon King, the male youth refused and demanded to return to his own world. As punishment, the kingdom imprisoned him. Now, Felmenia confronts the young man with her most potent magic, white flame, only to find it ineffective. The young man reveals himself as Yakagi Suimei, a powerful magician.

Isekai Mahou wa Okureteru! has been published digitally in English as The Magic in this Other World is Too Far Behind! by J-Novel Club since April 18, 2018.