Bakumatsu Kikansetsu Irohanihoheto

Both series has Edo period, katana-wielding action. Both have a more or less an aesthetic look to it (meaning it's a bit on the "pretty" side). Both series has a pretty interesting supernatural element to them. Both have a strong historical, driven plot line, yet the accuracy of the history used is naturally debatable. 

both are historical animes with a supernatural twist. there is also a "narration" of events that occurred during the period, which in Hakuouki is provided by Chizuru and Bakumatsu Kikansetsu Irohanihoheto by an actual narrator. later on in BKI events from Hakuouki "clash", such as Hijikata meeting with the other leaders, etc, are mentioned in both animes.  

Similar idea - different execution. In Hakouoki art is a little better, but Bakumatsu has no annoying female characters. Bakumatsu focuses mostly on the history adding a supernatural story-line as an attraction, whereas Hakouoki is using history as a background and focusing on the characters. 

Both are set in the same period of Japan's history and have some overlapping characters - Okita and Hijikata mainly but Kondou is mentioned briefly too. Both also have a heavily history-based storytelling with hints of supernatural elements to spice it up a notch.. without overdoing it. If you loved one of these you will probably love the other too! 

Both have a strong historical background (the ending of the swords' era and the beginning of the guns' era) Lots of sword fights A fantasy element  

Both shows are set in a historical time period with characters who are involved in the supernatural. I think that I enjoyed Bakumatsu more, but both shows give off a similar feel of tense fighting embroiled with supernatural elements. 

PMK isn't as dark or brooding as Bakumatsu is, but both are historical fiction. In fact, both include the Shinsengumi. PMK focuses mainly on the Ikedaya incident of the Shinsengumi and follows 15-year-old Tetsunosuke Ichimura as he goes out to avenge the death of his parents (he also meets Ryoma Sakamoto, who, in Bakumatsu, is Akizuki's master). The only negative thing I would say about this is that they over-exaggerate the blood spatter. 

Same time, same heroes, nothing special  

Both series are set in the same era in Japan's history with some overlapping characters like Toshizo Hijikata, Ryouma Sakamoto, Souji Okita, Kondou Isami and Tetsunosuke Ichimura. Both also have some characters who seek revenge on the one who killed their parents.. in a burning house. While both are based on history they have fictional characters added in and Bakumatsu Kikansetsu Irohanihoheto also has supernatural touches to it that are nicely woven into the story. While Bakumatsu Kikansetsu Irohanihoheto takes itself more seriously PeaceMaker Kurogane is slightly more light-hearted and comical. These series are both enjoyable, especially if you like historical (samurai) anime!  

A rurouni is brought into the lives of a small group and ends up in a fight to save the country. BOth rurouni have an idea about their honor, one being to never kill again while the other is to accomplish one particular task. 

Both anime have story placed in the same era (give or take few years), and both are historical with fictional "behind the scenes" plots. Both anime are also about samurais.  

Both series are period pieces with some basis in actual East Asian history, augmented with an inventive supernatural aspect and some creative storytelling. Bakumatsu Kikansetsu Irohanihoheto uses the end of the Tokugawa shogunate as the backdrop for an original story with original characters that weaves in and out of historical events; Koutetsu Sangokushi is largely based on The Romance of the Three Kingdoms which in turn is based on the end of the Han Dynasty in Chinese history. (Both timeframes are notable for their political turbulence, disunity, and action in battle.) 

Both are historical animes with a slight twist here and there. Chevalier d'eon focuses on pre-french revolution france while Irohanihoheto closes in on the history during the bakumatsu era in Japan. Both are enjoyable and you'll learn something! ^_^ 

Both are of-course historical anime. Both are based around in 'bakufu' period. While Irohanihoheto tries to retell history with a face of various supernatural occurrences, Tenpou finds itself meddling more with folklores.