From Wikipedia: A genius blond-haired Akuma who recently got transferred to Tomoharu school and was put into his care from the Akuma hunt. Her family profession is to study the Asura Machina control systems. She's a Luck-eater, an Akuma that eats the luck of people and controls the balance between unlucky and lucky people. She was sent to study the Asura Machina that had absorbed the Stabilizer. She also came to Japan to look for her missing sister. After exident in 7th series she appeared in 1st Worlgв 5 years ago in the past and helped Naotaka and Ritsu in their Asura Machina research. She created Hagane and modified Kurogane for Tomo.
Setsuna is a Shinmeiryu swordswoman from Kyoto who was taken in by Eishun Konoe, Konoka's father and the leader of the Kyoto Mage Association. She is childhood friends with Konoka and her protector. Setsuna spends the beginning of the series being relatively cold to Konoka, wishing to protect her from the shadows due to not forgiving herself for being unable to save Konoka when she almost drowned when they were kids. She does eventually open up to Konoka after the Kyoto arc and begins calling her "Oujo-sama" and "Kono-chan". Setsuna's pactio, Sica Shishikushiro is a wakizashi which she can summon and multiply at will to strike targets like missiles. Due to her training she's also skilled in anti-demon arts and is the one who taught Negi how to create shikigami from paper. Setsuna is a hanyou like Koutaro, in particular a crow. She was expelled from her people because white wings are considered a bad omen, and it was implied by Evangeline that she is an albino using hair dye and contact lenses to appear human. A running gag within the series is that Setsuna and Konoka appear to have romantic feelings for one another, yet Setsuna will deny it whenever she and Konoka are stumbled upon in romantic situations or asked about her preference.
Suika is the only oni currently living above ground in Gensokyo, with the remainder of the oni race living underground. Just as the folktales say, she has two horns on her head that symbolize her oni heritage, and enough physical strength to throw large boulders single-handedly. Her personality is jolly and quite childish as you would expect from her appearance. She also likes to drink and loves to party with all her heart. Her power in the games is to manipulate density. (Source: Touhou Wikia)
The elder brother in the Oomori family. He is obsessed with home electronic equipment, video recorders in particular. (Source: AniDB)
Two young sisters who took refuge at the Crimson Scholar's estate. Coming from a serf family of seven siblings, the sisters' other siblings died from hunger and disease. Due the harsh life of serfdom which their lord treated them like slaves, they escaped and hope to get a better life at the city. However, Chief Maid looks down on the sisters since their presence would bring trouble with the Crimson Scholar. Furthermore, she considers them "bugs" for allowing life harsh realities to control their fate rather than overcoming it and control their own lives as human beings and not thinking and planning their future. Upon asking the Chief Maid to teach them to become proper humans, they are taken unto her guard, working as assistant maids. Thanks to the education given to them, Big Sister Maid becomes knowledgeable about the different lives and social classes of human society while Little Sister Maid becomes an expert with food and drinks. Contrary to the knowledge of Hero and the others, they do not know the Crimson Scholar's secret.
Momotaros (モモタãƒã‚¹, Momotarosu?) is the first Imagin that gives Ryotaro his power, which allows for the Sword Form transformation. He can also sense when an Imagin is rampaging in the city, subsequently alerting Ryotaro immediately. His natural weapon as an Imagin is a sword named the Momotarosword (モモタãƒã‚¹ã‚©ãƒ¼ãƒ‰, MomotaroswÅ�do?). Momotaros blames Ryotaro for his Oni-like form, though it matches his personality, best described as hot blooded, arrogant, and comedic, serving as a foil to Ryotaro's own shy and cowardly personality. In fact, Momotaros is more interested in fighting than carrying out the Imagin's goal. Unfortunately, he is constantly beaten by Hana when he gets Ryotaro into trouble. When he possesses Ryotaro, declaring the words "Here I come!" (俺ã€�å�‚上ï¼�, Ore, sanjÅ�!?)[1], Momotaros's own personality takes over, giving Ryotaro power, confidence, and a bit of his eagerness for a good fight. His eagerness is shown in battle, where he always declares the words, "I am, from start (to finish), at the climax!" (俺ã�¯æœ€åˆ�ã�‹ã‚‰ï¼ˆæœ€å¾Œã�¾ã�§ï¼‰ã‚¯ãƒ©ã‚¤ãƒžãƒƒã‚¯ã‚¹ã� ã�œï¼�, Ore wa saisho kara (saigo made) kuraimakkusu da ze!?). Momotaros is also somewhat selfish, initially fighting alongside Ryotaro in order to ensure his own survival. Though he unknowingly places Ryotaro in unneeded danger to suit his fancy, Momotaros eventually learns to respect him and his desire to protect others. Though he demands respect, Momotaros is usually put in his place by Hana and her powerful punches. He also does not know how to swim, has a narcotic reaction to red peppers, and seems to be afraid of dogs. While he acts hostile and demeaning to the other TarÅ�s, he does care about them, proven by hiding his anguish while they are slowly disappearing due to the events of the Climax Scene. Momotaros is the base for Den-O's Climax Form, as he has control of the head and torso and can control the other sections that the other TarÅ�s usually have primary control of if need be. However, due to the newly-formed Junction Point, Momotaros's synch with Ryotaro is negated. However, his power is now accessed in the DenKamen Sword's Momo-Sword Mode. Since then, Momotaros makes it his task to train Ryotaro to fight on his own, being evasive on his reasons for it. But once Ryotaro learns the truth, both he and Momotaros have a falling out. Momotaros, enraged at Ryotaro for his decision to fight without the TarÅ�s, fights Den-O Plat Form to test if Ryotaro can really back up his words. After Ryotaro divulges his resolve, Momotaros apologizes to him for being evasive about the recent events and the two went on to destroy the Armadillo Imagin with the other TarÅ�s at their side. On his own, Momotaros can perform his style of Den-O's Extreme Slash, referred as "My Finishing Attack, Momotaros Version" (俺ã�®å¿…殺技モモタãƒã‚¹ãƒ�ージョン, Ore no hissatsu waza Momotarosu BÄ�jon).
Princess Peach is the ruler of the Mushroom Kingdom. She is often captured by Bowser in his attempt to take over as King.