Bakumatsu Kikansetsu Irohanihoheto (幕末機関説 いろはにほへと, Bakumatsu Kikansetsu Irohanihoheto?) is a Japanese anime series, created by Ryōsuke Takahashi and Sunrise. It was broadcast between October 6, 2006 and April 6, 2007 on the Japanese internet streaming channel, GyaO.

Source: Wikipedia