At the very least I'm glad I managed to do everything without a walkthrough... Speaking of walkthrough, I hope nobody minds if I post mine under here. It'll be hidden as it contains MASSIVE spoilers, but god was I struggling so I hope to help peeps.
Oh my god was this a hard roller coaster. I love the mystery genre, but the mystery genre is only partial to me. But I really enjoyed playing this visual novel, it seriously reminded me of Danganronpa and Ace Attorney, for some reason this was harder than I imagined it to be... Either way, I also love the characters. Claire was such a disaster I love her and her literal intelligence (I'm so sorry Claire that I fucked up things, but hey I got the Good Ending AHAHAHA), Laura at first I thought was a cool girl but god was she adorkable I wanted to laugh (and also cry because her arguement about the DD Thieves was the hardest for me), Sean at first was a nice character but upon his reveal I absolutely love him especially with how he's such a good partner for Claire, Latte? Poor guy was being pushed around, at least he got redeemed at the end by sharing his wisdom. But I'm still curious about something... Such as the motive to kill Vic?? I have a vague idea but not so sure.
Walkthrough Underneath!!!
I thought I'd help peeps with the investigation because I was also confused on parts of it. First, you gotta investigate everything and fill up your Notes, it's also a good thumb to investigate even the mundane things so you at least feel assured you investigated everything.
This'll follow the order of the discussions~! The first sentence will be the sentence/assumption you need to break while the second is the evidence/proof that you need to show in order to break it.
What Caused The Blackout? - A Lightinging Caused The Blackout: Transparent Outer Walls (Place it when Sean is asking why we didn't see the second lightning).
Who Caused The Blackout? - Someone Flipped the Breaker: Vic(tim)'s Whereabouts (Place it before Laura can claim that Latte flipped the breaker).
What Was Vic Hiding? - Vic's Jacket.
Laura's 'CoD' theory - ... Then Fried The Coffee Machine: Breaker System (Place on the line "How the coffee machine got burnt".)
After discovering that there was no electricity after all, choose: electrocuted by one of us.
What Evidence Supports That Vic Was Murdered? - Electric Burns.
Choose Ed, and then click on his Holster.
Ed's Defense - Actually, you need to play this round a second time just by reading, then Laura will come with another theory, how Latte could have been the murderer.
The Dashing Diamond Thief - Latte Caught Him And Attacked: Vic(tim)'s Whereabouts (Placed during Claire's "Latte did... during the blackout?".)
Latte's Secret - Cute Cafe Needed Money: Latte's Secret (Placed during "business was in the red".)
Why Did Ed Not Leave After Killing Vic? - Electric Locks.
What Evidence Proves That The Stun Gun Broke In The Cafe? - Coffee Machine.
Next, choose: the logo. Then, click on Ed's shirt pocket.
What Proves Ed Lied About Being Workmates With Vic? - Vic's Shirt.
What Was The Relation Between Ed and Vic? - Dashing Diamond Thief.