Tekken 8's story mode and character episodes have confirmed a popular fan theory that Reina is the illegitimate daughter of the former face of the series - Heihachi Mishima
Although most of Tekken 8's roster is made up of series veterans who have been given new moves and new looks, there are a few exciting newcomers that have joined the fight. As awesome as Azucena is, the most exciting of these is Reina, a mysterious young girl who uses the Mishima fighting style and has previously been teased to have a connection to Heihachi Mishima.
Prior to Tekken 8's launch, Reina's background has been treated as a bit of a mystery, with Bandai Namco previously stating that she is, "surrounded by mystery as the only known fact about her is that she is a student at the Mishima Polytechnical School". This mystery is one that's revealed as part of Tekken 8's story mode and Reina's character episode.
In the tenth chapter of Tekken 8's story mode, Reina is seen going up against Nina Williams, where she questions who she really is. Nina doesn't let us hear the answer, but it makes it clear that she's related to someone we already know. Considering Reina knows Mishima style and has a lot of the same moves as Heihachi, the answer has always been pretty obvious, but it's then confirmed in her arcade mode run that is unlocked after beating the main story.
Katsuhiro Harada has previously confirmed that Heihachi has multiple illegitimate children, which means there might be more fighters like Reina out there waiting to be discovered.
As soon as you start up the character episode, it's instantly revealed who Reina really is, as she's described as being the "secret daughter of Heihachi Mishima". It then goes on to say that she has a lot of respect for her father and that she's out to get Kazuya to prove his worth, seemingly not aware that he died at the hands of Kazuya in Tekken 7.
Reina's character episode ending has her imagining taking Heihachi's place after defeating Kazuya, before
Read more on thegamer.com