Watch for a nasty comment from the Japanese over this Biden faux pas. Freaking idiot
No, the Japanese are too much into haragei, meaning sending messages without actually saying them, for that. Expect some passive-aggressive act of non-cooperation some time between now and next January; my guess would be something to do with Takeshima or the Senkakus, the disputed islands in the South China Sea (I know those are the Japanese names, I'm too busy in sneaking off of work for two minutes to try to get the Sino/Korean equivalents).