Kenji can be found at the Casino.
You need to find a police car for this mission. Luckily, you can beat up the cop outside and steal his. Then, once you've lost your wanted level, head to 8-Ball's and get a bomb put in the car. You then need to park the car at the marker in the police compound. Arm the bomb and you can get in the Enforcer behind. The police car will then explode, and you can drive towards your guy for him to get in the car.
During the escape you should be able to reduce your wanted level by running over a Police Bribe in the tunnel. Ditch the Enforcer and get in a regular car once you are away from the compound. Use a Pay-n-Spray to get rid of the police, then finally go to the Hyaku Dojo to drop of Kanbu and complete this mission.
Reward: $30,000
This can be a very frustrating mission as the cars are not allowed to have a single scratch on it before it can be completed. Any damage you do will have to be repaired before hand. You have two sets of objectives to go to, red ones and a pink one. The red ones are the cars you need to collect: a Stinger, Cheetah and an Infernus. Take one, then give it to the garage (again, with no damage), then do the same with the rest. Once you have parked all of the vehicles, the mission is complete.
Reward: $25,000
Go to Newport to get a Yardie Lobo once you have accepted this mission. Next, head to the objective on your radar, and one of Kenji's associates will join you. Following this, you need to go to the hospital. Honk your horn to get people outside the hospital, then run as many over as you can before they realize what is happening. You then need to get out of the vehicle and take out all of the Colombians. Some trucks will also turn up, so destroy those too. Collect the briefcase and return to Kenji at the casino.
Reward: $25,000
Go to Torrington for this mission. Pick up the briefcase marked on your map, then get back in your car and go to the next one. This is protected by a single guy who you should have no problems taking out. Once he's down, take the briefcase and go to Belleville Park. Unfortunately, the briefcase that you wanted from here has been taken, so you need to locate the thieves and get your money. The gang is located in Portland, so go there to Hepburn Heights. You need to take them all out, retrieve the briefcase, and return to the casino.
Reward: $10,000
You need to kill eight dealers for this mission, each marked on your map. Go from objective to objective until you have taken them all out - killing them in any way you see fit but without attracting too much police attention.
Reward: $10,000