Wataru

Wataru is Lan's little brother. Although it's fairly obvious early on that Lan is adopted or something, it is never specified whether Wataru is the son of Dr. Komatsuzaki or what. (Given the revelation of Lan's past, it does not seem all that likely.) However, as Lan and Wataru consider themselves sister and brother, obviously they are.

After an "accident" at the Tokyo Grand Prix, Wataru received an emergency blood transfusion from his sister. (His blood type is B.) As a result of this, he developed telepathic powers that improve with use and some form of psychokinesis that is, in effect, increased strength.

In personality, Wataru is both the standard Type B person and the stock child character. However, his frequent worry over his sister is endearing, and he only really gets in over his head once. All in all, he is in no way as annoying as some of the child-mascots that anime series since the '80s were burdened with.

Wataru's seiyuu is Sasaki Nozomu, of Yuu Yuu Hakusho and BubbleGum Crisis fame.