Rinse rice with water. Drain well. Heat the oil in a medium saucepan with a tight fitting lid over medium heat. Add the rice and cook for 2-3 minutes, stirring frequently. Stir in sugar, salt. Pour in the coconut milk and water (the liquid should be about 1 inch above the rice). Bring to boil. Stir and reduce heat to low. Cover and simmer 18 to 20 minutes, until rice is tender. Remove from the heat and let sit for about 5 minutes, covered. Fluff rice with fork.
Heat the olive oil in a medium saucepan over medium heat. Add the onion and cook for 3 minutes, until tender. Add the garlic and ginger, and cook for another 2 minutes. Pour in the soy sauce, vinegar, tomato sauce, pineapple juice (from the can of pineapple chunks), and brown sugar. Bring to boil. Lower the heat and simmer for 5 minutes to combine the flavors. Remove from heat and set aside.
In a measuring cup or small bowl, stir cornstarch into the water until cornstarch is dissolved. Set aside.
Heat the olive oil in a large frying pan or wok over medium-high heat. Add bell pepper, carrot, and celery and cook for 3 minutes, stirring frequently. Stir in shrimp and cook, stirring frequently, for 2 minutes more. Stir in the pineapple chunks. Cook for 1 minute. Lower the heat and stir in the prepared sauce. Cook for 1-2 minutes, stirring constantly, until shrimp are pink. Pour in the cornstarch and water mixture and continue to stir until the sauce thickens and has coated the shrimp and vegetables, about 1 minute. Remove from the heat.
Microwave tortillas for 30 seconds or until soft. Place 3/4 cup coconut rice on warmed tortilla and top with 1/2 cup of shrimp and vegetable mixture. Roll into burrito. Repeat the process with the remaining tortillas, rice and shrimp/vegetable mixture. Enjoy!