In this, Inuyasha, Sesshomaru, and shippo are girls, harem, but Shippo is not in it, she will be daughter/little sister to the reader.

The reader one day wakes up with a screen in front of his face, and it explains that hes a gamer, he then gets a quest that tells him to go to a local temple with a well called the Bone eaters well. He arrives just in time to get pulled into the well with a girl named Kagome. He then gets a combat tutorial, where he gets a sword with a ice element affinity.

ID sanctuary enter and exit(allows user to enter a house in a pocket dimension, and invite others, as well as exit.)

ID Dungeon create and destory(create dungeons to train and collect items, and destroy them when your done)

Spirits: [As you kill monsters there is a chance that they will leave behind something called a Spirit that you can collect.]

[Spirits have multiple uses, all of them useful.]

[First of all you can equip them like accessories to boost your stats.]

[You could also merge a Spirit into a weapon or piece of armor to grant it special properties.]

[You could also choose to reform that Spirit into an item that is dependent on what the Spirit is.]

[Lastly, you could choose to summon the monster that the Spirit came from to fight on your side.]

[You can find Spirit's under the now unlocked Spirits tab in your menu.]

[There are two ways a Spirit can get stronger, the first is simply by using them as summons or accessories, the second is by merging Spirit's of the same monster. Once a Spirit gets strong enough it can evolve into a stronger form- So be sure to experiment.]
(I got this from a Highschool DxD self insert called, "Devils, Angel's, and A Gamer" on Fanfiction.net, go check it out)