If you're looking for manga similar to Niru Kajitsu: Strelitzia, you might like these titles.
Companies distinguish winners and losers according to the laws of economics established by adults. In order to destroy that system, the phantom thief Noel infiltrates the casino "Jailhouse"! No-one can escape her aim. The curtains open on the great thief show!!
This is the (imaginary) beginning story of the crazy popular Vocaloid Character GUMI!! By some freak incident, the now cyborg school girl has her eyes set on her idol debut as "Gumi" under the mysterious organization, "Intane Group"!?
The world we love is going to vanish. "You and me, we're one in the same." In front of Ainozomi Nakagusuku, a transfer student bearing a striking resemblance to herself suddenly appeared. When the girl mentions the whereabouts of Ainozomi's recently missing ex-boyfriend, inexplicable events threaten to change her life. Occult circles, doppelgangers, and mysterious disappearances.