Otona no Koi no Hajimekata

Overview

Matt is at his wit's end. As if he isn't busy enough with business transactions for the company he manages, he's left to take care of his ten-year-old daughter, Samantha, when his ex-wife passes away. Samantha rejects every nanny Matt hires. Just as the temp agency refuses to deal with him anymore, one of his employees introduces him to her younger sister, Tess. He learns that Tess is spending the summer at her sister's place, and he hires her as a nanny. She immediately befriends Samantha, but Matt doesn't expect to find himself falling for Tess's carefree charms...! (Source: Renta!)

Source: AniList