Try gooling SkyTree's tickets. The tickets can be booked before hand before u go there. Tsukiji is best go at 5am. Considering the nuclear leak in Fukushima... Do you still intend to eat seafodd there? a friend of mine living in Osaka (next to Fukushima) told me that they'd stopped eating seafood. You might only resort to chicken, beef, lamb and urmmm pork (if u are not a Muslim).