Japan has a huge mobile network that for many users, predicates the PC’s role as superfluous. However, that mobile network makes use of what Apple might call the ‘non-real internet’. If your needs turn you to that ‘non-real internet your user experience is at best turbulent and sometimes laughable. It just won’t do mobile internet with any semblance of reliability. Even some ‘real’ internet pages don’t display correctly, becoming a choppy and unusable mess.
The age old question still remains: what does one do when they must reserve shinkansen tickets from sites like express yoyaku? Answer, hop on a computer or use a phone that can only access the ‘non-real internet’.