* Read the initials of the default high score table in ''[=DonPachi=]'', top to bottom then left to right. They spell out "TOAPLAN 4 EVER", a tribute to the now-gone Toaplan, which was one of the most influential shmup developers and whose employees would go on to join other shmup-developing companies, including CAVE.
* Leinyan's ending in DaiOuJou [[spoiler:not even the government deactivating her and locking her in a research facility is able to stop her being with her love, her human pilot.]]
* The true endings of ''[=SaiDaiOuJou=]'' that occur for each character [[spoiler: after you defeat [[TrueFinalBoss Hibachi]]]] has your Element Doll vowing to stay by your side no matter what.
* If you think about it, TheStinger in the Xbox 360 mode of ''[=SaiDaiOuJou=]'' may have the Pilot coming to comfort Saya or [[spoiler: Hina being [[BackFromTheDead rebuilt]] and reuniting with Saya]], judging from Saya's smile at the end.