Ren is a quiet but vigilant boy who grew up under the care of his grandmother; he prefers to keep to himself and watch others from a distance. Ren's seemingly frigid nature is often perceived as indifference and apathy, thus tending to drive those around him away. However, Ren is known to care deeply for the people closest to him, choosing to express his concern in discreet with the smallest of good-natured gestures.
Having grown up without his parents, Ren spent most of his childhood in London with his 祖母 (grandmother) – the sole living relative of his family. In fact, it was within the four walls of his grandmother's cramped apartment, that Ren exhibited the first signs of being a magic-wielder. They had been accidents, really – ten year-old Ren hadn't meant to set his grandmother's favorite porcelain rug on fire, nor had he intended to shrink the poor neighbor's cat to the size of a plump pigeon.

The sharp gaze paired with unsmiling features present Ren as an unusually solemn child – though certainly one advanced beyond his years. Add to that, messy curls of an ebony shade and irises of a similar hue – Ren is the living depiction of what you'd call 'sullen'.
On the back of his hand, Ren bears a small scar from when he'd fallen into a bramble bush at the age of eight. Although Ren generally refrains from sharing details of his life with others, the story of how he'd gotten this scar is kept especially private.