|Allies||Shiro Miyata and Kei Makino (while human), Mina Onda (as a shibito)|
|Voiced by||Kei Kodama (児玉啓)|
She left Hanuda in favor of living in Tokyo. Returning to Hanuda to reunite with her sister,
Unknown to Risa, her arrival to the town occurred on the same night as the ritual to resurrect Datatsushi, and she is plunged into the alternate dimension with the other characters. She ends up relying on Shiro Miyata and Kei Makino in the Miyata Clinic, but things end up taking a turn for the worse there.
A young woman, 21 years old, is the twin of Mina Onda. While having lived in Hanuda originally, she left the village and went to Tokyo after graduating from middle school in order to experience a new, different life. However she spent many years stuck in the same dead-end job as a cashier in a supermarket,
She eventually became involved with someone from the entertainment industry and after receiving a letter from Mina, and still broken-hearted after almost getting herself into trouble for participating in an AV flees home, escaping her job and live in Tokyo.
She arrived at Hanuda the day before the incident, nearly at 23:00 she headed to the hospital to greet her sister Mina, who was late home; but on the way, at 0:00 the siren sounded and she lost consciousness as the village sinks into an alternate reality.
She regained consciousness at 4:00 in front of a house that she does not remember seeing, the Tabori house, and is confused as to where she really is and having lost all her belongings including the letter from Mina.
Risa hid behind a bush at a corner of the house when she realized that there were shibito in the area, namely a sniper shibito at the main door, but she eventually finds the way to distract him and escape.
She literally bumps into Shiro Miyata, Mina's lover. When she finds out who Miyata is and that they were both looking for Mina, she accompanies Shiro back to the Miyata Clinic, Shiro’s family hospital (that ends up being the hospital from 1976, not the one from 2003).
As they enter, Risa is overcome by a mysterious sense that her sister is with them, and looks outside a window to see her distant body looking towards her. Despite this, Shiro does not notice this, and when Risa looks back at the window after looking at Shiro, Mina is gone. Hours later, Kei Makino, priest of the Mana religion, bursts into the room to see if Shiro has seen Tomoko. She notes that Shiro and Kei are twins, Risa realized that she and Mina are not the only pair of twins in Hanuda.
Risa search alone to find her sister in the hospital, armed with only a flashlight. Walking down an empty corridor, she hears the voice of Mina, and finally meets Mina…who has transformed into a horrifying Shibito Brain.
Scared, Risa outruns her twin and uses sightjacking to discover that Shiro and Kei in the midst of conversation. She pulls a fire alarm to alert the brothers of her predicament. Kei tries to rescue her, but is scared stiff when Mina turns her attention to him. In the nick of time, Shiro runs up to Mina and attacks her with a bottle of acid to the face. Mina runs off in pain and Shiro tells Kei to watch over Risa while he himself goes to hunt her down.
During Shiro’s manhunt, Risa expresses concern about Shiro’s safety. Kei comforts her by saying that he’s usually late, so there is a chance that he’ll turn up safely. The same cannot be said for the two, as Mina knocks out Kei, having infiltrated their room, and uses the telepathic link that she and Risa share to show her twin the truth about Shiro – the doctor had killed Mina when he found out that she was pregnant with his child.
Risa is then overcome by her sister’s stronger psychic link, and acts like a Shibito. Dressed in a nurse’s outfit like Mina, she corners Shiro in a room and Shiro strangles her, noting how she looks just like her sister in death. Her link with Mina results in her becoming a Shibito mere seconds after she dies from strangulation, and proceeds to chase Shiro around the clinic; Shiro eventually defeats them both and practices an autopsy on them, to see if Shibito can be permanently killed.
Kei enters the autopsy room upon hearing the Onda sisters’ screams, and finds out what Shiro has been doing to them.
At some point during day 2, after regenerating from the experiments, she escaped the Clinic and bathed in the red water, evolving into a shibito brain just like her sister. Then they both hide in the mines of Gojaku peak.
They confront Shiro, who by this point is wearing Kei’s clothes on day 3, but he is able to stop Risa’s tracks permanently – immobilizing Risa by planting a stake in her chest, though she is still able to struggle her arms and legs in vain.
In the final hours of Day 3, Shiro breaks the dam destroying the shibito nest and in the process killing Datatsushi, then he goes to the river bank and uses the Uryen, offering his own life to free the lost souls of the Failed Shibito. The Onda sisters find peace and appear to Shiro as humans again in the Uryen's flames, smiling and forgiving him. He follows them, falling into a hole created by the Uryen.
As a human, Risa is nervous about being in Hanuda because of the shibito; When she finds Mina as a Shibito Brain, she is scared of her sister coming after her and is forced to call for help. Nonetheless, she is also quick-minded and able to use distractions to her advantage; in her first level, she escapes the Tabori house by distracting the sniper shibito at the front pathway.
She is surprised at the sight of another pair of twins in Hanuda.
Immediately after her transformation into a shibito, Risa laughs madly at Shiro, her murderer. She, like other shibito, pursues any living person she can find.
- Sister of Mina Onda; finds a Shibito Brain Mina, who uses her telepathic abilities to show her what Shiro did to her; her mind is taken over by Mina; autopsied with Mina; confronts Shiro in mines with Mina; freed with Mina by Shiro.
- Accompanied by Shiro Miyato to the Miyato Clinic; later killed by Shiro before resurrecting as a Shibito; autopsied by Shiro alongside Mina; confronts Shiro in mineshaft before being impaled by a stake in the chest; finally freed from Shibito form by Shiro.
- Meets Kei Makino in the Miyato Clinic; Kei tries to come to her rescue after being alerted by a fire alarm; is with him for some time before he is knocked out and she is transformed by Mina; he discovers her after Shiro’s autopsy of her and Mina
Day 1 04:00
Taburi, abandoned building
Escape from abandoned building
Discover Mana Cross
Day 1 22:00
Miyata clinic, ward 2
Warn Miyata and Makino of approaching enemies
Find angel statuette
- Her background story was based on an AV actress that the director Keiichirō Toyama likes, called Kurumi Morishita (森下くるみ). Sato created Risa's backstory based on her.
- The Onda surname is taken from "Yappari Neko ga Suki" (やっぱり猫が好き · We Really Like Cats), a sitcom from the years 1988-1991, featuring 3 Onda sisters (Kayano, Reiko and Kimie) who share a house with their cats.
- The name Risa might come as a pun from Lisa Garland; a character from Silent Hill which is also a nurse just like Mina Onda. (The creators of Silent Hill are also the creators of Forbidden Siren).
- Risa's only weapon, the umbrella, is the weakest weapon in the entire game. It may even be considered a joke weapon by the creators. This weapon is reintroduced in Forbidden Siren 2, accessible for Akiko Kiyota, but is much more effective in combat than with Risa's.
- Has multiple scenes in which she slides through semiclosed doors or windows and is able to easily glide past enemies exploiting a glitch with the action menu.
- The aspects of Risa as a recurring normal Nurse Shibito and being staked in the town mines near the end of the game as a Brain is reused for Yukie Kobe in Siren: Blood Curse.
- Risa's second mission is the only mission where more than one companion is available, are also the only male companions to be had, and where they cannot be reached nor harmed.
- There is little to no gap in her death and resurrection as a Shibito; that may have something to do with the telepathic link Mina had on her, as Mina is a Shibito at the time
- Even as a shibito she is always in the same levels as her sister Mina (Except in Tabori and Arato).
- Risa always starts her missions in an unsafe starting position where the player is required to move her elsewhere to a safer location. Risa's first mission, though safe at first, is not a good hiding place as she will eventually be discovered by a Shibito. Risa's second mission starts with being discovered by Mina Onda, where she has only seconds to turn around and flee before she is caught and killed.
- Appears in the timeframes Day 1, Day 2 and Day 3
- The only level where she is a companion character is in Shiro’s mission in the market in Day 1
- A majority of scenes involving her were set in Day 1
- She only appears in Day 2 & 3 as a Shibito