Senchou, Mondai Arimasen!

A romance that begins when an abusive company president, Hiroumi, time-slips onto a 17th-century English ship. Confused, Hiroumi is called "Captain" by those around him, seeking instructions. Unable to return to the present and clueless about the situation, Hiroumi is determined not to become a useless incompetent and resolves to rise to the occasion...

Source: Natalie, edited