Upvote:4
In order to answer your questions for others.
Yes, you can send a Yuu-pack and have it delivered to the post office in the manner you described in the question. Regular mail can also be delivered in a similar manner, see image on the link you provided.
If you don't have a phone number you should be able to leave it blank.
Please note that the post office will only hold it for 10 days.