Take 1 bunch of scallions (roughly 6 whole scallions) and slice the top dark green parts at a diagonal, very thinly. Set those aside for garnish. Take the 2nd bunch of scallons and slice off the dark green parts. Save them for another use. Slice the 2 bunches of remaining scallions, which are now just the light green & white parts.
Heat 2 tbsp neutral oil in a large pan over medium-high heat. Add the diced carrots and saute for 1-2 minutes. Add the light green sliced scallions and continue to saute until very fragrant and the carrots begin to soften. Roughly 5 minutes.
Add 2 cups cooked white rice. Don’t mix the rice in yet. Push the entire contents of the pan to one side, leaving enough room on the other side for the eggs.
Lower the heat to medium, then pour in the 2 whisked eggs. You may or may not want to add more oil to the eggs. Continue to cook and scramble the eggs until they are firm. You’ll want to get this to a hard scramble, rather than a soft scramble.
Season the entire pan with a pinch of salt and a few good cracks of black pepper. Pour 3 tbsp soy sauce directly onto the white rice in the pan. Use a spatula to mix everything together, breaking up any clumps of rice.
Once fully mixed, season with MSG. Taste and add more salt as needed. Continue to fry the rice for 3-5 minutes. Once the rice is finished, lower or turn off the heat. Then add 2 tbsp butter and toss until fully melted.
For the Yum Yum Sauce: In a small bowl, mix together 3 tbsp Kewpie mayo, 1/2 tsp ketchup, 1 tsp rice vinegar, 1/4 tsp paprika, 1/4 tsp garlic powder, 1/2 tsp sugar, a pinch of salt, and a dash of MSG. Whisk until smooth. Add a splash of water to thin out the consistency as desired.
To serve, add the rice to a plate, drizzle 1-2 tbsp of yum yum sauce over the rice, then garnish with the diagonally sliced scallions.