Once in Japan, there wasn't much time to sightsee - or to visit family, in Ken's case - because the team had to get right down to business and act quickly. They planned extensively, and once it became time to begin the operation, Ken was more than ready to end this. He was no longer the kid he was before.
Laura had come along to offer her help, as well, since it was the least she could do. She worked in the background to provide a distraction, while Ken was on the front lines with the rest of the team. Ken and the team made their way through the HQ, which is an entire story in itself, but they made it to Miharu's inner sanctum, and fortunately, just narrowly missing disaster, they were able to neutralize her and talk her down - All with the power of empathy (and a particularly powerful spell). Ken reunited with Shay and Laura on the helicopter landing pad with many tears and hugs. They did it. They actually did it. Everything they had been through wasn't for nothing, and the three of were alive, in one piece (more or less). That was what was most important to Ken.
With the completion of their mission, it came time to claim their reward. To their surprise...Arkship kept up their end of the bargain. They were each given their favor. With Ken by her side, Laura gave back what she had been given and squandered. The ritual was painful, but necessary - Although now without magic, Laura could live on.
Before leaving Japan, Ken and the team made their rounds with visiting family and celebrating. Ken's parents weren't very pleased about him not calling all these years. What? He's been a busy rockstar!
In any case, it came time for Ken and the Good Samaritans to go home, and put all of this behind them.