Pros
Nice offices, free food, tokyo is great.
Cons
Rakuten is truely infested with staggeringly bad management. Its suffered from all the true talent leaving, whilst the un-educated or interns from 10 years bad are now left to run the ship. Rakuten runs a very good marketing strategy, and likes to sell a very different impression than reality itself. Its hugely successful at that. However, working on the inside, its a very bad place to be if you want to further your career or actually deliver something. Japanese can be very stubborn, and simple things take literally years to be agreed upon, and in the tech industry it will destroy your career. This isn't a place for foreigners to thrive, so be warned. Also, i would add, that the office itself is WAY too over-crowded - which is really to do with the massive amounts of hiring they do to keep the backward paper/manual/excel processes alive. The CEO is very active in talking to employees every week at 8am in the mandatory meeting ( which impacts negatively on your reviews should you not attend ) - Hes often a key-note speaker on events and topics which really he knows very little about. Its quite amusing in that respect. Its a lot of hype and its a matter of time before the whole machine is exposed. Unless you are just after a visa for residence in japan, I would stay well clear. Don't say you weren't warned its NOT a tech-company.