Ojousan to Yobanaide

Misaki, whose father is the president of a company, has always been alone despite leading a wealthy life. Her father has entrusted his capable subordinate, Miyashita-san, to look after Misaki! Even though Misaki is confused about living together with the handsome older man on sudden notice, he keeps his calm demeanor and says "this is just work." But while living together with him, she starts to notice her heart racing more for the slightly ditzy and very kind Miyashita-san...

(Source: MangaDex)