No More Heroes 3

I beat him at my second try. I would add that you have to play with a "Mario Kart" mentality: drift in every turn and every corner, because you get little speed boosts that help you reach Ryuichi easier. The downside is that obviously you risk crashing against the walls and losing health.

There were reports that with the recent December patch update, you no longer need to get gold medals on all 6 bike missions to unlock the Ryuichi fight (only Silver and up). But from my personal experience, this appears to be false. It wasn't until I got gold on all 6 bike missions that I received a notification that the "dragon road" mission was available at the Thunder Dome. So this guide is still correct.

As for the Ryuichi boss fight itself, it took me like 10 tries to beat. It's pretty annoying since any time you make contact with the invisible walls, even during a turn, your engine (in the top left corner) takes damage. If you take too much damage the fight ends immediately. You have to destroy 3 vehicles by ramming them before Ryuichi even shows up and any damage sustained will still carry over. Basically you need to drift and use nitro as much as possible but manage your nitro meter; do not spam it. Draining the meter will result in periods where you can't boost at all and cars will leave you in their dust. You should drift during turns and hit nitro for that extra boost while avoiding Ryuichi's attacks. If he starts dropping bombs, you can boost into them and knock them into Ryuichi for extra damage. Even with all this in mind, Ryuichi still needs around 10 hits to be defeated so practice, memorize the track, avoid hitting walls, manage your nitro meter, and you'll defeat him in time.