|This article is about a character in Hotarubi no Tomoru Koro ni.|
Tsunemasa Tadamura (忠村 常雅 Tadamura Tsunemasa) is the youngest of the Tadamura brothers.
Younger brother of Masashi and Nobuteru; the youngest of the three brothers. He lives a free-spirited life, imitating a backpacker. A so-called bachelor and aristocrat.
(Translated from the official website.)
Tsunemasa has black hair and tan skin. He often wears collared shirts.
Tsunemasa is very relaxed and easygoing.
Tsunemasa is the youngest of the Tadamura brothers, born and raised in the village of Hirasaka. Like his brothers, Tsunemasa left the village because he was tired of following the customs and beliefs. He reunites with his brothers and their family when Grandmother dies and attends her funeral.
- Masashi Tadamura (oldest brother)
- Nobuteru Tadamura (older brother)
- Terumi Tadamura (niece)
- Teruya Tadamura (nephew)
- Yukito Tadamura (nephew)
- Yue Tadamura (niece)
Tsunemasa greets Yukito when his family reaches Grandmother’s house. At dinner Tsunemasa and his brothers discuss Masashi's family situation and some of their childhood in Hirasaka. Tsunemasa watches over Grandmother's body that night and falls asleep. The next morning, Tsunemasa is surprised to see Grandmother's body missing even though he was in front of it all night. The family soon finds there are two suns outside and the electricity doesn't work. Tsunemasa tries to drive into town to tell the police and comes running back to the house on foot. His car stopped working all of a sudden and he had to abandon it. A fog has also started rolling in that induces headaches by standing near it.
Tsunemasa goes scavenging for food with his brothers and gets separated from them while running from a gakiban swarm. He enters a woods and sees a naked woman calling for help. Tsunemasa rushes to help her and winds up cutting himself on some bushes, which have suddenly developed razor-sharp leaves. Tsunemasa keeps going on despite his wounds to help the woman only to find she disappeared. Tsunemasa stumbles out of the woods and regroups with his brothers, who carry him home while getting attacked by dogs. The family has difficulty tending to Tsunemasa's cuts since they keep festering and won't close.
Tsunemasa condition worsens despite the rest he's been getting. He learns about the protective charms and remembers that Grandmother made some for her friends, so there should be more located around the village. Later, a mist river manifests near Tsunemasa, who is just staring at the ceiling. The group is forced to relocate to another house.
Tsunemasa seems to recover a bit from his wounds, however he refuses to eat and drink. Terumi and Yue realize he's entering a similar state as Chiharu. That night, Tsunemasa goes through the family's canned food and eats most of it before throwing up. He licks up his own vomit as everyone else watches on in horror.
Yue and Terumi bring Tsunemasa and Chiharu outside for some fresh air but Tsunemasa suddenly runs off. He enters a nearby abandoned house and eats feces from the toilet in it, horrifying Terumi. Tsunemasa runs off again somewhere else.
The group learns about how Hell works and that some deceased are only able to feed off of feces and waste, which matches what happened to Tsunemasa. The family goes to Hell's Cauldron and finds Tsunemasa buried there with his brothers. After they pray for them, the brothers' expressions calm and they pass away.