How does Xbox friend request work cross platform?

If a person on Xbox 360 sends a friend request to a person on Xbox one, will that person see the friend request on xbox one? I need to know cause I sent a friend a friendrequest and it still says pending.

On the 360, in order to be friends with someone they must accept your friend request. This isn't the case for Xbox One friends - you can add them without them adding you.

The Xbox Support site indicates that you can add Xbox 360 friends while on the Xbox One:

Keep in mind that friends you added to Xbox 360 will show up as both friends and followers on Xbox One.

However, a friend that has been added on Xbox One will not automatically show up on your Xbox 360 list. If you plan to play with them on your Xbox 360 as well, you will have to send a friend request through your Xbox 360 console. Once they accept, you can see them on both of your consoles.