Mizuki would probably have some fashion blogs and few Amazon tabs open on her laptop. She likes to browse shopping sites for fun, but it usually results in a couple impulse buys. She also likes a couple beauty gurus on YouTube, but she's picky. And she often doesn't realize there are a lot of tabs open until her browser looks like this.

And Mizuki's cellphone is total chaos. She has a vibrant wallpaper and a bunch of apps all over the place, none of which are in folders. But she knows where her favorite apps are and that's all that matters to her. Lots of social media and casual games installed. Not only is her phone being blown up with notifications from her apps, but also by messages from friends—both from real life and online. Her phone is her happy place.

The search history on Nick's computer is full of old police records (likely inspecting them for telltale signs of supernatural activity), the locations of local car shows, and a link to Letterboxd. His watchlist and profile is full of old corny westerns, some of surprisingly good quality and others really only good for a good chuckle. Lots of baseball stuff, planning out when he has the opportunity to either see one of Sam's games or take him to another.
(He also seems like the type to have a spotify library full of nothing but smooth jazz.)

A large amount of digital download non fiction books

A ton of research on various topics that interest him as he's a smart lad.

Of course there'd also be tabs open of cool knives he has found randomly, both practical and well made ones and those really badly made ones tryin to look super badass and all. Cause he's not supposed to have knives it sounds like but that doesn't stop him from looking I wouldn't think.

Yep, throw in a bunch of toku music and it's 100% accurate :p

A tons of Tokusatsu shows like Kamen Rider and Super Sentai in his computer. Ran from actual every single episode to fan arts and stuffs like that.

_ _____

Totally correct! Mostly self-recorded porn whenever he doing it with his boyfriend.

Porn to deal with frustration. Threatening unsent texts and letters. Confessions of passion and self struggle. Photos of memories long since past. 

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That sounds about right! He is a little information sponge. I LOVE the idea about the sticky notes omg that's too funny and has to become Canon for him! 

A bunch of tabs for links from this, and perhaps something like Space Email open. They probably just use internet explorer... for some reason.

Probably a lot of Pirated music, Bread facts and cat videos. Maybe even extensive documentaries on humans and the human condition. 

Lots of tutorial videos, random crusty jpegs of cats, and midi files of assorted vocaliod songs.

Youtube videos about crafting jewelry, makeup tutorials- a lot of saved images of jewelry patterns she's found on the web as well as quite a few yahoo answers/quora guides on hiding bodies/concealing murder evidence.

probably a lot of cooking videos (since he is a chef), though he seems like he might like things like knife sharpening/restoration or watch that one guy who makes knives out of literally anything.

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edit: completely valid vv

He probably would have a whole folder of heavy metal songs he illegally downloaded off of the internet with a YouTube to mp3 converter

Oh yeah he would also have a giant folder of cursed minecraft images