A great game - but be cautious!
Identity V, in itself, is not an inherently inappropriate game. In the main quick match part of the game, you work with others (teamwork) to escape the hunter if you are a survivor. If you play as the hunter, you try to catch the survivors and prevent them from escaping. There isn't any sort of blood or anything violent in that sort of sense. I'd recommend the game to young (mature) teens and above. If you're an adult seeing if they game is appropriate for your kid, IDV is, but there are some sensitive topics I'll discuss you may want to take note of.
There are in-app purchases for currency called Echoes which can be used to buy things. You don't need them to get things in game, though; you can use Logic Points and Fragments which are totally free. The game does not try to show Echoes down your brain and are actually pretty good at letting you buy things in-game without any purchases. It should be noted the "essences" you open to get cosmetics and in-game items could be seen as "gambling" but it's just a standard gacha system featured in other games such as Genshin Impact. It's not bad but you should be aware that if you are an adult, your kid may want money to get something from one of these, and often they can be quite pricey!
There is a chat system - a global chat, chat with friends, chat with people in your matches, etc. This is one part of the game you should be wary about if you want your experience to be appropriate. While usually the chats are pretty harmless, in the global chat in particular, there are sometimes conversations about unpleasant topics. These are not limited to sex/suggestive topics, racist/homophobic ideas and some slurs, bullying, etc. Of course, this does not represent all of the fanbase and you can block people and report them, but the chat is one of, if not the most toxic and most inappropriate part of the game itself. I would recommend just staying out of it and ignoring it. As a player who goes in the chats a lot myself, they don't really seem to bother me. This is why I'd recommend that players are mature to some degree.
Another sort of questionable area are the backstories and the lore of the characters, survivors in particular. The survivors and hunters have their own backstories, and they aren't all sunshine and daisies. Some of them cover topics such as deaths of loved ones, violence, etc. These topics can be sort of serious and uncomfortable for some, but in general, I don't believe them to be bad. If you triggered by anything they could be unpleasant, but for an average person they shouldn't be too bad (sometimes it's even hard to figure out what's happening in their backstory without searching a proper explanation on it).
Another important part is character designs. Some of the hunter designs, although relatively tame all around, and be unsettling to some people. The game is meant to be a sort of horror game so this should be expected. None of the hunter designs are too bad, but if you're sensitive, they may make you uncomfortable.
Overall, I'm a big fan of Identity V and I think it's great for a wide variety of people. The game and mechanics are easy to learn and easy for all ages to play, my rating is just higher due to some of the sensitive topics it has. Of course, whether this game for you or not is totally up to your own opinion and you shouldn't just take my word for it. The game has a great and creative community and cast of characters, and I would highly recommend this game to others.