Rika is a sub-character in Mystic Messenger who founded the RFA and was V's girlfriend and ex-fiancee. V the co creator of RFA, claimed she committed suicide a year and half prior to the events of the game. Yoosung mentions to the player that she threw herself into the ocean but a body was never found and nobody witnessed her suicide.
On the outside, Rika is often described by the RFA members as someone who is bright, strong-willed, and charismatic person. She is said to care deeply for others and wanted to help them achieve happiness, which is the sole reason for her creating the RFA. She is also capable of inviting many people to her parties, mainly due to her great influence on others. Many people don't know but she can be easily persuasive and manipulative.
Unknown to most, Rika is severely mentally ill. She struggles with depression, anxiety, paranoia, and (paranoia induced) delusions. (Many make claims that she has schizophrenia but there is no factual evidence to prove this and it was never confirmed.) She tries her best to hide this from all except V, the one she trusts most.
As time goes on, her mental condition worsens, only to be intensified by the death of her dog, which she blames herself for. She starts to believe that she can be a savior, and has to rescue everyone from the pain and sins of this world. She ends up doing harmful things to those around her. She brainwashes many people and blinds V. She shows evidence of knowing her actions are wrong and that she is control of her actions.
"Rika" is only a pseudonym, and her real name is never revealed.
Within the Casual and Deep Story routes, the player has limited information about Rika. When the player (MC) first joins RFA, the player is presented with the knowledge that Rika had passed away one and a half years ago due to suicide by drowning. However, just like where she lives, the facts about her death were also so secretive and easily triggered suspicions, such as nobody ever seeing the corpse, V being the only witness to her drowning and so on.
Rika was the one to originally bring together the RFA and was the one to start the charity events for the RFA. Most of the members in the RFA are grateful towards Rika and viewed her incredibly favorably. The other RFA members reportedly went in the chatroom much less after she 'died' and the messenger only becomes active again when the MC joins.
However once the player reaches the secret endings, much of her past is shown.
Rika was adopted by Yoosung's aunt and uncle after they couldn't conceive. However, it appears as if their family life was far from happy, with her aunt going so far as to telling Rika that she regrets adopting her.
At some point, Rika visits one of V's galleries and becomes enchanted with one of his photographs, to the point where she begins going there every day, which V eventually notices. He approaches her and begins talking to her, mentioning he sees her staring at this particular photograph every day, to which she states she feels happy and loved when looking at the picture.
V then introduces himself, after gaining an interest in how she spoke and offers the photograph for free in return, they'd go out for coffee, eventually leading them to begin a relationship.
The players then find out that Rika had lived much of her life with paranoia, depression, anxiety, and , which later skyrocketed once her dog Sally died, with Rika blaming her death on herself for not going through with the surgery, picking the 'natural' way. By this point, V sends her to see a therapist to help her cope with her anxiety/depression/paranoia/ which Rika only sees for three weeks before she decides to stop.
At this point it is hinted that she harms herself shown in the images of the scene. [[File:IMG 2092.JPG|thumb|556x556px|No signs of cutting are shown. Many people mistaken the shadows from V's hands as cuts but they are clearly shadows.
Eventually, Rika reaches a point where she feels as if she is compelled to save everyone, telling V that she feels better and that she's stronger and can handle herself now. This brings forth the concept of Mint Eye's ideals, V doubts Rika, and is against the concept of Mint Eye, to which causes a fight between him and Rika, leading to her leaving and injuring V.
Secret Ending 1 & 2
During Secret Ending One, it is revealed that Rika is the founder of the cult Mint Eye (deemed as 'savior'). She is shown as being deeply disturbed and fixated on 'cleansing' the world and saving people. The players are also introduced to more of the backstory of Rika, and how she ended up as she is now. Rika then later reveals that she originally planned to bring all of the RFA members to Mint Eye.
Rika seems to despise V at this point, calling him a traitor for being involved with RFA, stating that she's glad he's blind because she'll be free to do whatever she wants. This is evidence that V was not involved with Mint Eye for a long time since in one visual novel she even talks about how he's been spying on Mint Eye. However, V is still madly in love with Rika, stating she can 'destroy him' all she wants.
Further into the first secret ending, Rika hopes to be able to brainwash Seven implying that he is much better than his brother, Unknown. As well as stating she had no plans to kill Seven despite promising him she would. This greatly angers Unknown as he was entirely against it, as he was wanting to kill him for revenge for 'abandoning him'. Rika then scolds Unknown for disagreeing with her, implying he has no use to her now, causing great mental damage to Unknown.
At this point, Rika sends her disciples to brainwash Unknown some more, but Seven intercepts between the two, shocking Unknown before he faints due to his wound. Unknown then pulls out his gun, eventually shooting V, which causes Rika to come back to (somewhat) reality and grieves for V.
At the end of Secret Ending One, Rika is standing far from V's funeral, Yoosung mentioning that ever since his 'suicide', she stopped talking. However, she begins talking about V being the sun, and how he is always with her.
Within Secret Ending Two, Rika is now being taken care of by Yoosung as the doctors believed it was best for someone from her family to take care of her, rather than a round-the-clock doctor. Yoosung and Zen watch her within her shared apartment with V taking photos and smiling, stating she is similar to that of a child with how happy she is.
After a while, Zen has a prophetic dream about her and tells Yoosung to send Rika away somewhere without informing Jumin and Jaehee. It's implied they do this in her best interest, and she will be better off wherever they sent her.