The Dragon's Betrothed(2016)

Kamisama no Uroko

Being called "Sensei" all the time and having to act worthy of it was too heavy a burden to bear, so I fled to my home town. But amidst the nostalgic scenery, a mysterious man appeared before me...

Rin, the water dragon god to whom Chiharu has been betrothed, can be disarmingly friendly and charming, but inside lurks an animalistic ferocity. Knowing that he can’t escape Rin’s protective embrace, can Chiharu make himself fall in love with the god instead?

(Source: SuBLime Manga)