Tonari no Shugoshin

Orphaned at a young age, Rio has spent her life fiercely independent, raising her younger brother entirely on her own. Having learned early on that relying on others is futile, she trusts only herself to navigate the world. Her pragmatic outlook shifts unexpectedly when she acquires a rare playing card—a Jack of Clubs modeled after the legendary knight Sir Lancelot—hoping to secure a profitable return by auctioning it online. However, the purchase brings far more than financial gain. That very night, Rio encounters Sir Lancelot within her dreams, sparking a recurring vision that greets her every time she falls asleep. The boundary between her nocturnal encounters and waking reality begins to blur in ways she never anticipated. Her carefully guarded independence faces its greatest test when a boy named Yuuki asks her out on a date. As the romantic encounter escalates and he leans in for a kiss, the impossible happens: Sir Lancelot suddenly materializes in the physical world. Stepping directly into her reality, the legendary knight boldly declares that he has arrived for one purpose—to save her.