Minato (Protagonist): Ghost. Posts occasionally, but mostly just keeps up with the blogs of his friends. When he does post? Audio posts and personal posts about how his day went or what he did. Sends kind messages anonymously.
Junpei: Memes. Of course it's memes, what else would it be? Also, cute girls and baseball stats.
Yukari: Varied content, posts whatever she feels like posting. Always replies to her friend's personal posts, and sends them asks frequently. Selfies are common. Tends to vagueblog when upset.
Mitsuru: Keeps close tabs on the rest of S.E.E.S. and confronts them when they're blogging instead of working. Mostly factual posts or news. Fact checks each post thoroughly. Occasional opinionated and long-winded rants on sensitive topics.
Akihiko: Fitness blog. Lots of posts featuring tips and tricks for exercise regimes, and inspirational (albeit very cheesy) quotes. Occasional selfie to show off progress.
Shinjiro: His main blog is overexposed black & white photos and hard rock audio posts, with occasionally dark aesthetics. His side blog (anonymous) features lots of home-cooking recipes and puppy vines.
Fuuka: Softly colored photos, flowers, and general good vibes. Follows Shinjiro's side blog unknowingly. Personal posts always under read mores.
Aegis: Reposts everything Minato does. Always corrects misinformation, often when she doesn't understand a joke. Gets excited when she does understands a joke online, and makes sure to point out that she gets it in the post itself.
Ken: Posts a lot of gifsets and art from his favorite shows and games, and fan theories about each. Makes personal posts when he's fired up, usually vague. Unfortunately, reposts memes from Junpei.
Koromaru: He's a dog.