Gunjō SenkiGunjō Senki.

Gunjō Senki (群青戦記; "Record of Ultramarine") is a Japanese manga series written and illustrated by Masaki Kasahara. It was serialized in Shueisha's seinen manga magazine Weekly Young Jump from August 2013 to June 2017. A sequel, titled Shin Gunjō Senki, written by Kasahara and illustrated by Azychika, was serialized in the same magazine from January 2021 to March 2022.