Getting Lenneth Valkyrie
Complete the Corridor Of Distortion dungeon to have Lenneth Valkyrie join your party.
Tamaki Nami sings theme song
Witness Tamaki Nami's transformation and immediately speak with her in the Night and Desire Street at 6:00 p.m. She will join you. Do not have her in your party, then visit the Red Lotus Bar at night. Tamaki Nami will sing the game's opening theme song.
Star Ocean 2 reference
Notice Gantz's appearance during events that feature him throughout the game. His outfit will begin to resemble that of Claude from Star Ocean 2 during the intermission sequences.