From Comic Sylph's Official Homepage:

When Suzu, the daughter of a wealthy family, finds herself lost, she procures the help of bad boy high schooler Haruto, and from this encounter, the two become close. However, Haruto is now in the crosshairs of one Shinohara, Suzu’s butler.
But it seems Shinohara himself harbors a past he doesn’t want his mistress to learn of…