^Really? Tenso now offers regular airmail as well? Thought they only offer EMS! Only found this page regarding shipping method:
http://www.tenso.com/en/guide/deliver/index.html
As for what's inside, they wrote the following in the email (and I don't like the fact that they opened it and checked everything, feeling kinda weird)
-- Package information (1) --
Sender : エイベックス
Item (description) : Bag
Number of items : 1
Price of items : 0 yen
-- Package information (2) --
Sender : エイベックス
Item (description) : Clothing
Number of items : 1
Price of items : 0 yen
-- Package information (3) --
Sender : エイベックス
Item (description) : Towels
Number of items : 1
Price of items : 0 yen
-- Package information (4) --
Sender : エイベックス
Item (description) : Sundry articles
Number of items : 6
Price of items : 0 yen