Kaito is the Japanese cousin of Logan Mitchell. Kaito has the power of super speed. He is currently the fastest being alive. He was given powers by a radioactive incident in Japan his DNA, Adrenaline gland, and natural electrical current were radiated.
The day after he found he could shock his molicules and vibrate them so fast he could phase through things but with practice he could phase through time and space. But not enough to completly travel through it but he could create a path where he could travel faster then light because he could travel through it. When he travels in superspeed the world is shown as a big field glowing bright gold and it automaticly turns off when he reachs the destination he wants which is usually shown as a big bubble in the portal.
Also the reason he dosen't colapse from exhaustion from traveling through light is because his Adrenaline gland is supercharged so much that he can barely feel tired. Unlike beings like Logan who can barely be seen when using superspeed when Kaito uses superspeed his body glows gold and when he passes a place the sudden flash of light and then its absence makes it seem like all other light is sucked out.
Kaito and Logan have a good friendship but that dosen't mean they haven't had a disagrement before. One time Kaito and Logan had a fight about whether they should save a terrorist from Negative 101. Kaito tackled Logan so fast that they flew to Egypt from the impact, severly damaging a pyramid in the process. Or when they were saving a train from crashing into a building Kaito got competitive and did a sharp turn to save it himself Logan almost wasn't fast enough to stop from crashing into the building himself, then Logan got into a heated argument with Kaito and they then tried to headbut eachother and the contact was enough to crack the ground and send them both to oppisite sides of the earth with Kaito getting traped in antartica because the force from the headbutt was enough to temporarily mess with his brain's electrical current and therefor disable his ability to go into superspeed. He came back in season 3 and stays the rest of the series he seems to have the ability to heal faster than normal humans.
In season 3 he acts cold towards Alex but later he seems to kill Alex by jamming a steel rod in him at his highest speed but the body falls down and is revealed to be an shapeshifter with the real Alex being locked in a cage in Negative 101s lair. In the next season he blows up a paper processing plant for no good reason then runs to an unknown place then Logan tries to run after him but he manuevers in a big circle and punchs Logan back to Blut city.