1) The micrometeorite thing bothered me until there was a quick mention of the ion shield which normally destroys micrometeorites, apparently.
2) The lead-up to launch flashback with the evacuations and "trust the prime minister" were VERY reminiscent of Fukushima Daiichi to me.
3) Being a sumo fan has taught me one thing about spoken Japanese: every vowel is pronounced. Most words sort themselves out more or less.
4) Surely the solar sail would be segmented so if there WAS a tear that was unrepairable(I would think repair robots could be used), it would only affect a small portion of the sail. Additionally, if part of the sail did get torn, they could pretty easily vector themselves so that they're still pointing in the same direction, much like if you've ever seen a plane land/fly in a strong crosswind. There may be a problem braking at the other end, but again, vectoring should help/fix that.
5) I didn't need to know about Mars/Moon being destroyed. They're mostly dead rocks that would be very difficult to inhabit without a lot of preparation. Given a choice between a 300 year trip to a distant habitable planet and a 2 week or 2 year trip to the moon or Mars respectively, I'd pick the long trip I think, given the fact that there are further resources to be gathered from Earth.
6) The sacrifice at the end BUGGED me. Firstly, he was the last Japanese person in existence, and he just throws that away? That's like putting your go stone directly in the middle of your opponent's main group. I know that's not legal or possible, but you know what I mean. Here's why the sacrifice was so stupid:
Solar sails accelerate VERY SLOWLY. Especially if they were so far away that the sun was "just another star". Just letting go of the sail or pushing himself back towards the main craft would have gotten him close enough for someone to rescue him pretty quickly. His relative speed to the craft was zero, so even just a 5 km/hr(5 ft/s) push would have gotten him back in 20 hours. If he had any fuel left at all, he could be back in MUCH less time than that. A good squirt of acceleration, and then drifting for a couple of hours. EVA navigation is tricky, and "catching" someone is difficult, but not impossible.
I may fire up Kerbal Space Program and see if I can EVA a Kerbal back to his ship from 100 KM away with just a jet pack.