The Prodigy Knight and The Repeater Knight

The Reason to Fight

The Visitor From the Old Haunts

A Maiden's Battle

Arisuin Nagi

The Rebellion

Initial Match

The Glory of The Knight

Total Control

The Oath Under The Moon

Before The Storm

Disciple

Happiness' Form

Second Step

Twilight of Disaster

Father and Daughter

A Knight's Pride

Worst One VS Sword Eater

A Knight's Long-held Desire

Memories of Summer

An Icy Smile

Shizuku's Challenge

After the Battle...

The Feelings Between Them

Their Future

The Mystery at Okutama

Messenger from the Other Side

Worst One Under Siege

Father and Son

Arranged Duel

Facing The Darkness...

Crownless Sword King

Entrusted Feelings

Training Camp

Chance Meeting

Amane Shinomiya

Scheming Maneuver

Big Sister and Little Sisters

Outbreak of War

Akatsuki on Stage

Siblings

Difference in strength

Difference in Power

Undeniable Feelings

Indispensable feelings

Frenzied Battle

Lorelei

Witch of the Deep Sea [Lorelie]

Their Vows

The Vow Between Them

Omake

In a time and place where one's soul can be morphed into a weapon, there are modern-day magicians called Mage-Knights. Although Kurogane Ikki is a student at an institution that trains Mage-Knights, he has no particular talent in magic and is labeled the "Failure Knight" or "Worst One." Getting way less than average marks in the scorings, he was forced to repeat a year. But with the arrival of a new head of the institution, a new rule was created: knights whose abilities are compatible, as decided by the board, must share rooms and attend practice and training together throughout their school years to bring up their abilities to the max. It is a rule to implement the absolute verdict of ability.
 
Ikki's roommate, Stella Vermillion, turns out to be a princess of another foreign country. Stella is a Rank A knight: the type of genius in magic who only appears once a decade. When Ikki walked in on her while she was changing her clothes, it caused a huge misunderstanding, which eventually ended up in a duel between the two of them. The punishment for the losing side is Eternal Submission to the winning side.
 
Forced to live the same room and practice magic together throughout all their school years, how will Stella and Ikki's relationship evolve?
 
Note: Includes the epilogue and 2 extra chapters.