Okay before you guys get mad at me! I've been a web developer for 10+ years now and have good knowledge in managing websites and building them!

Below is some super simple ideas to make Hianime better! These implementations take max of a day to implement and can really improve the site!
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1) Ajaxify the site! What this means? When commenting or replying to a comment, comments should show instantly without the need of a refresh just to see them! Same goes for the notifications. Super simple to implement and makes a whole lot of difference!

2) Flag button for community posts and comments! Implementation is super simple! Add a database table to the comments that store flags! When 3/5 users flag a comment it either gets deleted or put under review for a mod to see it? Scared this might get abused? then simply sending a notification to all mods when a comments reaches 3 flags is suffice!

3) Better error handling! Show users what keywords are banned in comments, so users don't get confused when comments don't go through!
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I know Hianime didn't create the websites backend, as you can simply purchase this website script on code canyon! But with a bit of know how and working on the backend can really improve the users experience 10 fold! The site as it stands is a solid 8 out of 10! But why not aim for 10 out of 10? Your users will love you for it and the devs can be proud of what they've built!