The Irie Clinic (入江診療所 irie shinryōsho) is the only medical clinic in Hinamizawa. It is named after the doctor in charge of it, Irie Kyōsuke. Takano Miyo is employed as a nurse there.

Many characters, like Keiichi and Ōishi, remark that the clinic is suspiciously large for such a small village.

In Minagoroshi-hen and Matsuribayashi-hen it is revealed that the clinic is just a front, and it is actually a research facility run by Tokyo named the Irie Institute with the purpose of studying the Hinamizawa Syndrome. The research team was assembled by Irie and Takano, after they found they had a common interest in the research of parasites that affect the brain.

Thanks to Tokyo's interest in potentialy transforming the Syndrome into a WMD, the institute was given tons of funding, according to Akasaka, a large amount of tax payers' money was diverted to the institute every year, which lead him to return to Hinamizawa to investigate. Tokyo also sent a highly skilled force named the Yamainu to help keep the institute a secret.

Tomitake's role is to supervise the research's progress and report back to Tokyo, Irie's role is to lead the research efforts and decide how to act should things go wrong, Takano's role is to assist Irie in the research and command the Yamainu. Irie is supposed to be the head of the institute, however, because of Takano's position, she holds considerably more authority than anyone within the institute.

Because of their participation in the research, Irie and Takano were given honorary JSDF (Japan Self Defense Forces) ranks, Irie treats this as just a formality and considers himself a normal researcher, while Takano fully embraces her position and uses it to her advantage.

Takano wishes to prove her grandfather's research right, and Irie wishes to save people from potential tragedies caused by brain disorders. In order to speed up the research's progress, the institute kidnaps and dissects several villagers in the highest state of paranoia (L5).

Unfortunately, at one point, Tokyo decides to shut down their plans, and plans to completely cut the budget of the institute within the next three years, they order the research to focus on developing a cure, effectively wiping out the pathogen, rendering Dr. Hifumi's research useless.

This sends Takano into a state of panic, from there, she begins her plan to wipe out all the villagers by killing "R," in order to cause a huge disaster that would be recognized as the True Curse of Oyashiro-sama, ascending her grandfather's studies into the realm of the Gods.

The surface of the clinic is normal, appearing as a regular clinic, although it also acts as a hospital. Hōjō Satoko was once hospitalized there for her terminal Hinamizawa Syndrome, and dismissed. The interior of the clinic is furnished well, with paintings and potted plants. It is unknown whether or not this facility contains an X-ray generator above ground, though it is almost certain that it has this and more underground.

The clinic closes at 6:55 PM every day, while the opening time is unknown.

The basement contains an advance security system that includes a near-perfect surveillance system, a counter-intrusive gas release system, and a large research lab.

Although the surveillance system is supposedly flawless, it did not observe Akasaka's existence and his entering into Rika's household, causing the Yamainu and Takano to face problems in Matsuribayashi-hen. The security system is also able to pick up which member of the clinic's ID is being used to gain access to the underground facility.

The gas counterintrusive measures start once a red emergency button is pressed, alerting the facility of intruders. In 120 seconds a suppressive gas is released, either killing or knocking out the intruders. Staff members are provided with a gas mask, and while the facility is preparing to release the gas all electronically controlled exits are closed. The gas that is used itself is unknown.

The most important part of the underground facility is the research labs, where Irie and his fellow researchers study the Hinamizawa Syndrome. It is well equipped, supposedly possessing an electron microscope of its own. Multiple operating rooms are down in this area as well. It is also within this area that vivisections on terminal patients are carried out.

The facility is accessed via ID cards, with the hospital members and the Yamainu being able to access it.

Within the underground facility also lies a comatose Satoshi, at the end of Matsuribayashi-hen he is still hospitalized there, though he is frequently visited by Shion.

Irie Klinik pt-br:Clínica Irie