Reimu is one of the most known heroines from Gensokyo, and as the sole maiden of the Hakurei Shrine, she is commonly called upon (or calls it upon herself) to investigate strange occurrences throughout Gensokyo. Through time there were powers that were unawakened for her at her first debut to her homeworld, she grew more capable to manipulate powers she has today, and much more. Reimu is commonly described as easygoing, curious, dutiful, and optimistic — sometimes overly so; she's also short tempered when offended and can be hard to comprehend with, except when near other girls or youkai. Her personality seems sympathetic toward many individuals; there are few characters who remain her rivals past the first encounter. Her shrine has become a moderately popular locale for some of Gensokyo's residents.

While rather lazy in her free time, she is highly devoted to her duties as the Hakurei Shrine Maiden, resulting in a "shoot first and ask questions later" attitude to youkai extermination.

It's been stated that Reimu treats everyone the same, whether they're humans, youkai or gods, giving them no particular respect or disrespect. This habit has caused her to inadvertently befriend many youkai she defeats. While she tries to keep youkai away from her shrine, this is because it makes it harder to do her job rather than because she dislikes them. This leads to a major theme in the Touhou Project, that of the relationship between humans and youkai in Gensokyo.

 

http://en.touhouwiki.net/wiki/Reimu_Hakurei

 

Miraculously of an unknown secret to all, Tashki and Reimu appear to be one and the same by mind, heart, and soul. But this also states that Tashki is simply Reimu of "another Gensokyo", thus proving an unknown Theory and truth that's yet to be known to all.

 

The True Identity

Though Tashki is unknown upon any origins, it is later revealed that she is none other than Reimu Hakurei of her Gensokyo.

 

With the Theory of More Than One Gensokyo, proven to be true by the Hakurei Miko, Tashki/Reimu now seeks a new goal for herself while remaining as a shrine maiden and a convenient swordmaster: Find the other girls of her Gensokyo, and find her/their Gensokyo.

 

Though she has memories of her Gensokyo and herself, she doesn't remember entirely

of everything while she searches for the others with Ichimo, Nomika and Moses.