| Kimiyoshi Natsumi|
|Alternate Name||Tōdō Natsumi, 藤堂 夏美|
|Nickname||Nattchan (used once by Ōishi Kuraudo)|
Early 20's in Epilogue
Higurashi Daybreak Weapons
|Portrayed By||Kaori Mizuhashi|
Kimiyoshi Natsumi is the main character in Onisarashi-hen, and in the two Higurashi no Naku Koro ni Kizuna Arcs: Someutsushi-hen and Kagebōshi-hen. She makes a cameo appearance in the Matsuri version of Miotsukushi-hen while Hōjō Satoko is unconscious in bed and appears as a character, together with Minai Tomoe, in the Kizuna version of the same arc.
Natsumi is the daughter of Kimiyoshi Haruko and Kimiyoshi Tōji. They recently moved from Okinomiya to a city with Natsumi's grandmother, Kimiyoshi Aki who is a native of Hinamizawa and devout believer of its local deity, Oyashiro-sama. She becomes friends with classmates Saeki Chisato and Makimura Tamako and develops a crush on Tōdō Akira, who likes her in return.
After the Great Hinamizawa Disaster, many former Hinamizawa residents begin to act strangely. Ōishi Kuraudo and Akasaka Mamoru come to Natsumi's house to talk to her grandmother who they heard was from Hinamizawa. At the time, however, she isn't home. She is taken to a restaurant and is questioned by them. Akira comes by them and says that people wearing school uniforms can't go inside restaurants. Outside, Natsumi thanks him, and he volunteers to take her home. Upon arriving at her house, there are talismans all over it. Akira walks away, and Natsumi runs into her house. Her grandmother is performing rituals to cleanse her family (such as drowning puppies), and she calls her mother. The next day, she tells Akira that her family is related to the Hinamizawa incidents, and he believes her.
One day, after arriving home from school, she sees her grandmother being attacked by Haruko. In the end, her grandmother dies. Haruko suggests cutting her into small pieces, so they can hide her better. At school, the next day, her friends notice her behaving strangely and note that there's a rumor circulating about Natsumi being from Hinamizawa.
On her way home from school, she sees a news cast about a body of an elderly woman being found. Upon arriving home, she sees her mother beating her father for hiding the body in an easy-to-find spot. After she leaves the room, Natsumi's father suggests calling the police. However, Haruko comes back into the room and stabs her husband's neck. Then, she decides to kill Natsumi.
Akira calls Natsumi's house from a payphone and hears someone screaming for help. Upon arriving at Natsumi's house, Haruko seemingly strikes him with a vase. Natsumi tries to wrestle the knife out of Haruko's hands and Haruko accidentally slices her own neck open in the struggle. Natsumi is rescued by Akasaka and the police and Natsumi apologizes to Akira for lying to him.
Later, when Akira confronts her, it is revealed that Natsumi's testimony was fabricated, and she was actually the one who killed her family. In a fit of psychosis, she ends up stabbing him in her confusion. However, shortly afterward, she realizes that Akira is the only important thing she has left.
In Onisarashi-hen's epilogue, it is revealed that Natsumi was being cared for by other members of the Kimiyoshi family for a few years. However, they believed she was cursed by Oyashiro-sama and had her locked in a room filled with talismans, bound and blindfolded. Akira saves her and they get married and move to a small, rural town. She was too unstable to live in a house, so she lives in a local clinic where Akira visits often.
Natsumi has liked Akira ever since she first saw him. Akira goes as far as forgiving her for killing her family and stabbing him in the stomach. He even tries convincing her it was he himself who killed everyone to relieve her guilt. Later, in the epilogue of Onisarashi-hen, they are married.
In the visual novels, it was revealed that Mion and Natsumi know each other. Despite living in Hinamizawa, Mion was often seen working part-time in Okinomiya, where she sometimes met with Natsumi. Depending on the player's choices, in Higurashi no Naku Koro ni Matsuri, Natsumi may appear on the Watanagashi Festival where she has a friendly chat with Mion. In Someutsushi-hen, Natsumi reveals that she's always looked up to Mion and was even a bit jealous of her for being the firm, leader type who is able to have conversations with adults like equals, even though they far older that her.
- Natsumi was voiced by Kaori Mizuhashi in three Higurashi video games, Higurashi no Naku Koro ni Matsuri, Higurashi Daybreak, and Higurashi no Naku Koro ni Kizuna.
- She does not make an appearance in the Higurashi no Naku Koro ni anime.
- In the PSP port of Higurashi Daybreak and Higurashi Daybreak Mega Edition, Natsumi teams up with Hanyū.
- In Someutsushi-hen, it was revealed that Natsumi is part of the Kimiyoshi Clan, one of the Three Great Houses of Hinamizawa, and the mayor of the village is her distant relative.