Diagon

Senshi, those bestowed with absolute magic that can manipulate their soul as a weapon called "Buki." These Senshis undergo training in Academies that develops this Senshis to become an aspiring Magical Warriors. Seno Yukio is currently training to become a magical warrior in Tinrelts Academy, despite being a F ranked Senshi - the lowest possible rank

One day, he stumbles upon Yui Asano, a blue haired, S ranked girl nicknamed the Thunderous Predictor. The underlying obligation is to respect S senshis by either bowing a little or saying a greeting. Seno Yukio Didn't follow such rule,

"Hey stop right there." Seno stopped,

"This is my first coming in this academy but disrespect already?"

"Disrespect? on you? why?"

"it is a rule in academies to respect S ranked people right?"

"That rule doesn't apply to me, I only respect people that deserves to be respected"

"Then let us duel to tear that little world of yours"

"Suit yourself then"

That was the beginning of the story of Seno Yukio, a F - ranked Senshi