Chapter 819 is now out!
My thoughts on events right before Murobashi Etsuto is found dead:
Noto Taisaku --
- seems frustrated as his bell doesn't seem to be working
- difficult to see inside the room, but nothing looks suspicious
- closes door same time as Etsuto
- closes door before Idenami complains about sound
Murobashi Etsuto --
- peeks out of room to see what the commotion is about
- is talking to someone on his cellphone
- holding phone in left hand
- closes door same time as Taisaku
- closes door before Idenami complains about sound
Idenami Mari --
- complains about a sound (cellphone?) from inside her room
- has tea kettle and cup set out on table
- refuses to let conductor inside room
Komino Natsue and Sumitomo Hiroka --
- both exit room just as conductor is distracted by Idenami's sound problem
- head off in opposite direction unnoticed
- difficult to see anything in room
Andou Satoru --
- enters hallways while Idenami is still complaining
- enters hallway asking what's the matter after Komino and Sumitomo seem to have left
- closes door behind him after entering hallway
- difficult to see anything in room
My thoughts on actual discovery of body:
- (pg. 15) [upper left] third link from left on chain seems thinner than rest of the links
- (pg. 15) [bottom left] same link mentioned above is the one that breaks
- teacup set out on table in front of Murobashi, but no kettle is in sight
- teacup seems to be empty and handle is facing right, indicating Murobashi drank from his right hand
- note, gun is also in right hand and that cellphone was used in left hand
- cellphone used previously not visible
- pistol grip seems to be accurate
- a small, black object seems to be on seat opposite to Murobashi
Overall thoughts:
I'm terrible at deductions, so I have absolutely no idea who it could have been. I really doubt Noto and Idenami are the culprits, because they seemed truthfully frustrated at the broken bell and the sound respectively. I'm suspecting Komino and Sumitomo as well as Andou. The two ladies seemed to have cleared the hallways awfully fast, which brings me to suspect they might have entered another room in the hallway. Andou also closes the door to his room and walks toward the conductor and Idenami, which isn't something you'd do if you were just wondering what the commotion was. That's pretty much all I can get from this.