Checked on 21 October 2026 against the Steam store page and the Final Demo, before the 22 October 2026 launch. Steam app 4413070 by Tohakusha Inc. Forum dates are UTC.

Short answer. Tsumimi is the streamer whose livestreams you watch and steer; a Tohakusha post written in Tsumimi's voice describes the streamer as "the chainsaw girl of Wataame Chainsaw" [S2]. Mashiro is Tsumimi's former partner, and Red Chat Ritual is about the truth behind Mashiro's disappearance [S1]. You play a viewer [S1]. A streamer reading the demo's fan site gave the ages of the two as 19 and 18 [S9]. In the sources read for this page, no other character is named; an unnamed agency [S15] and an unnamed man [S14] appear in the INCIDENT REPORT posts.

The cast at a glance

CharacterRoleWhat the sources say
TsumimiThe streamer you watchTohakusha's post of 6 July 2026 quotes Tsumimi: "I’m Tsumimi, the chainsaw girl of Wataame Chainsaw" [S2]. Gematsu (9 April 2026) writes "a struggling idol streamer" [S7].
MashiroTsumimi's missing former partnerThe Steam store text names "her former partner, Mashiro" [S1]. Tohakusha's post of 14 September 2026 says "Mashiro, Tsumimi’s former streaming partner" [S5].
The viewer (you)An unnamed fanThe Steam store text says "As a viewer, intervene in streamer Tsumimi’s livestreams" [S1].
Wataame ChainsawThe idol groupTohakusha's posts name the group [S3]; Gematsu calls it an "idol unit" [S7].
The agencyAn unnamed organisationINCIDENT REPORT #01 says the agency announced that "Mashiro has been unreachable since leaving her home" [S15].
A man in the woodsUnnamedINCIDENT REPORT #03 says Tsumimi "spotted a man in the woods" [S14].

Tsumimi

Tohakusha's own posts speak in Tsumimi's voice. On 6 July 2026 the post opens "Tsumimi-chiwaaa!" and ends the introduction with "the chainsaw girl of Wataame Chainsaw" [S2]. In that post Tsumimi says that "Mashiro still hasn’t been found" [S2].

Third-party previews describe Tsumimi from Tohakusha's launch material. Gematsu, on 9 April 2026, wrote "a struggling idol streamer" who streams in the hope of becoming famous enough for Mashiro to find Tsumimi [S7]. Automaton West, on 9 April 2026, also describes Tsumimi as a small, struggling idol livestreamer [S8]. These are press summaries, not Tohakusha's wording.

Mashiro

Mashiro is the reason the game exists. The Steam store text sets the case as "the disappearance of her former partner, Mashiro" [S1], and says "your favorite streamer" [S1]. Tohakusha's 14 September 2026 post asks what happened to "Mashiro, Tsumimi’s former streaming partner" [S5]. Tsumimi's 6 July 2026 post says "The real Mashiro still hasn’t been found" [S2].

In the demo, the opening is a fan's monologue. Naishi Sukui's video (15 June 2026) shows it at [0:20]: "Mashiro pulled me out of my funk" [S11]. The same video reads out the group's name as "the idol unit cotton candy chainsaw" at [0:20] [S11], while Tohakusha writes the name as Wataame Chainsaw [S3].

The fan-site profiles read in the demo

Streamers who played the demo read out a fan-site page with a short profile for each of the two. These are automatic captions, so name spellings vary; in the video of DrTaco1982 (19 October 2026) a caption reads "her name is Sumimi" [S10].

  • Tsumimi's profile. In the video by Rem Inverse, the caption at [12:40] has "who is 19 years old" and "outwardly cheerful and carefree" [S9]. The same caption continues with "low self-esteem" and "strong possessiveness" [S9].
  • Mashiro's profile. DrTaco1982 reads at [9:41] "18 years old, introverted, easily pushed around, low self-esteem" [S10]. Rem Inverse gives the same age at [12:52] ("who is 18 years old") [S9].
  • The hiatus notice. After the profiles, Rem Inverse reads a notice at [13:13] that says "the group will be going on temporary hiatus" because of Mashiro's disappearance [S9]. A fan comment follows at [13:43]: "I read the announcement, but I still can't accept Mashiro's disappearance" [S9].

DrTaco1982 was unsure how the page labels the two: "it says Mashiro over here and then her name is Sumimi" ([9:30]) [S10]. This page does not settle that from captions.

The losers

Tohakusha's 6 July 2026 post addresses the audience as "my dear losers" [S2], and other posts describe the name in two ways. On 24 April 2026 the post says "losers" is a "cute fan name" for the idol group Wataame Chainsaw [S3]. On 12 May 2026 a note in the BitSummit post says "The Losers" is the "official fan name for the idol Tsumimi in this game" [S4]. The two posts differ on whether the name belongs to the group or to Tsumimi; both are Tohakusha's.

The agency and the man in the woods

Two unnamed figures appear in Tohakusha's INCIDENT REPORT posts, which are announcements and not demo content. INCIDENT REPORT #01 (29 September 2026) says the agency announced that Mashiro "has been unreachable since leaving her home" and that it is investigating the situation with the police [S15]. INCIDENT REPORT #03 (2 October 2026) says Tsumimi "spotted a man in the woods", and asks whether the man is connected to Mashiro's disappearance [S14]. The full run of reports, in date order, is on the incident reports page.

Voice and art

Voice acting arrived in the Final Demo: Tohakusha's post of 28 September 2026 says "The Final Demo finally has voice acting" [S6]. Twiins iink (video of 28 September 2026, played on "an early version of the full demo") says of Tsumimi's performance, "she does do a good job" at [1:26] [S12].

On the art side, Automaton West (9 April 2026) names "character designer Wata, known for designing the model for Nijisanji VTuber Hyakumantenbara Salome" [S8]. For the 100,000 wishlist mark, Tohakusha's 6 July 2026 post says it received "a special illustration from KEI, the illustrator known for the original character design concept of Hatsune Miku" [S2]. Tsumimi's comment on it: "It almost looks like Tsumimi and Mashiro are really here together" [S2].

How much of the cast the demo shows

Tohakusha's 6 July 2026 post says the free demo lets you watch the stream "until partway through Day 6" [S2]. The Final Demo "lets you play through part of DAY7" [S6]. Tohakusha says the Final Demo shows a small part of the story [S5], so what the demo tells you about Tsumimi and Mashiro is an early part of the cast's story. For what you do in those days, see how to play.

What players say

Players read the pair's bond in their own way. The Steam store text calls Mashiro "her former partner" [S1]. GfTookMyDog (24 June 2026) wrote in the forum, "Tsumimi is 100% head over heels for Mashiro" [S13]. x0mbi333 (28 July 2026) replied "fr they would be the cutest couple" [S13]. These are two players' opinions, not Tohakusha's statements.

Sources and version

Checked on 2026-10-21 against the Steam store page and the Final Demo, before the 22 October 2026 launch.