Star Ocean 5 we won't see at E3. It's too Japanese and niche and weird to get the spotlight treatment at such a mainstream event. Same with Summer Lesson, which is so downright pervy that it wouldn't jive well with the audience that'll be present.
Persona 5 is definitely a possibility, and I'd love to see a gameplay trailer get shown during the conference, but that's up to Sega.
There's something weird going on behind the scenes regarding Gravity Rush. We know now (sort of) that a PS4 remaster of the first game is on the way, but Sony haven't officially made it known yet. At the same time, God of War III Remastered, which was leaked around the same time, got its announcement trailer soon after, so Sony clearly weren't shy about making that known to the masses. We also know for sure that Toyama is working on the sequel, which was (sort of) revealed at TGS '13 as a Vita game, and then quickly disappeared into obscurity, presumably because at some point during development Sony decided to rebuild it as a PS4 game instead.
So my thinking is that Gravity Rush Remastered will be announced at E3, while the sequel isn't properly revealed until maybe TGS this year, because it's still a long ways off. Or, GR:R gets announced at some point between now and E3, and then the sequel gets its showing at the E3 conference, but that sounds more like wishful thinking on my part. Either way, we've got to see something substantial of Gravity Rush in some way, shape or form soon.