Pros
Pay is high for Tokyo market. Flexible work hours. Nice place to collect a pay check so long as you keep your head down, and don't plan on fixing anything. There is also a good volunteer program, and nice office events. Handful of strong engineers to work with and learn from.
Cons
Engineering department is in late-stage bozo explosion. Inept management with poor technical skills and zero desire to fix anything unless there is an obvious way it can be used to win points with upper management... and sometimes not even then. It's mostly risk aversion: better to leave a system broken than fix it and risk exposing other broken things. You get to watch/play the blame game whenever things break, or sit in meetings and come up with a good story that leaves the team/manager/org looking innocent. I think some people call this politics. No hope for decent management as anytime there is an opening, management promotes a technically deficient individual contributor that is unlikely to upstage them by doing any meaningful work. If you try to transfer to a less dysfunctional team, your transfer might get blocked by management with some really flimsy reason given for why you weren't selected for an opening on another team - this actually happened to someone recently. HR might listen to your complaints, but they will do absolutely nothing. In the worst case, if your complaint is about a manager, they will work with that manager to make it go away. One manager was reported for sexual harassment, with zero consequences, then the same manager started hiring more and more young women, using "diversity and inclusion" as an excuse. Am expecting that #METOO moment any day now..