In Another World with My Smartphone, Vol. 9 (manga)

Determined to get revenge on the genera who reflected his every attack, Touya prepares for battle. But before he can strike, he’ll have to arrange a meeting with two of the most powerful men in the world—the emperor of the Regulus Empire and the king of Belfast! There, he tells the two rulers of his plan to retake the imperial capital, but unbeknownst to him, Lucia, the Empire’s third princess, has a very important request…