Chicken Teriyaki with Sushi Rice

I'm afraid, my friends (I know we're not friends but I kinda need some so just go with it) I've been lying to you. When I've been asking for soy sauce, it turns out I need to be more specific; light and dark soy sauce actually differ massively in flavour and purpose. How stupid I was thinking light soy sauce was just a healthier option, which was why I avoided it- after the consumption of low-fat mayonnaise and 1% milk I learned that they do sacrifice taste for healthiness. Dark soy sauce is for colour and sweetness, whereas light is actually more salty, and gives quick seasoning. Light soy sauce is also better for cooking quickly into noodles or a stir fry, as it's not too dark and thick, and adds gentle seasoning and a good hit of umami, not the viscous, cloying quality of dark soy sauce. However, it is best for marinades, and a thick treacly sauce like this, so the dark stuff is what you want here.
In terms of other ingredients, I was sorely disappointed that no Asian groceries provided sake- a strong Japanese rice wine, so I had to go for the cheap, synthetic stuff that Asda provides. It's fine for cooking, and I shall be happily in the future, but not (not for me as I can't drink alcohol anyway) for drinking,  it tastes like honeyed sawdust. This is the only ingredient you may have difficulty stocking, the others can all be found easily in supermarkets but I recommend an Asian shop, partly because the taste is more authentic and partly because I'd rather support an Asian grocery than add to Tesco's preparation to take over the world.
 Traditional teriyaki uses whole chicken thighs, grilled with the skin on but here for ease of making and eating I use whole chicken thigh fillets with no skin but a bone or two isn't a disaster. Whilst I would usually prefer breast meat in something like this, I do think the slightly gristly and fatty quality of the meat is part of the dish. I'm also not being entirely traditional here, as sesame oil is not in every recipe, but I like a quick slick of it at the end just before you serve it. You have to add it here as the flavour will be massacred in the hot wok otherwise.
1)Mix together 4 tablespoons of sake, 125ml mirin, 125ml dark soy sauce, 4 tablespoons sugar, 3 mixed garlic cloves, and about 3 cm of minced, fresh ginger. Put 700g chicken thigh meat, bone in or out and skinned in the mixture, coating it well. Leave it to marinade for a good 20 minutes out on the counter or even overnight in the fridge.
2)Prepare the sushi rice, place 1 cup of sushi rice into a saucepan, and swirl it in water 3 times, then rinse it in a sieve until the water runs clear. Add 1 1/3 cups water, bring it to the boil, then clamp on a lid and simmer it on a really low heat for 10 minutes adding more water if it's catching, then turn off the heat and let it rest with the lid on for 25-30 minutes until it's dry. Give it a good fork through before you serve it.
3)Remove the chicken from the marinade, and fry it in a little peanut or groundnut oil. Vegetable oil is fine, but a nut oil is best for Asian cooking. Sear it until golden, then add the marinade and cook until fully done; to check if they are, cut open the largest chunk with some kitchen scissors, there should be NO pink.
4)Lift the chicken out of the pan with a slotted spoon, and keep it in a foil package until it reunites with the sauce. This keeps it hot and tender. Over a gentle heat, reduce the sauce until it thickens and goes really syrupy, but keep tasting it to make sure it's not burning. It's so dark you wouldn't be able to tell. Mix the chicken back into the sauce, and serve it with your sushi rice, some raw spring onion or cucumber strips and a drizzle of sesame oil and sesame seed sprinkle.