Yu-Pack; Japan Post domestic parcel delivery service
Trademarked name for Japan Post's domestic parcel delivery service. Often used generically to refer to sending a parcel via this service.
この荷物はゆうパックで送ります。
I'll send this package by Yu-Pack.
ゆうパックの料金はサイズと重さで決まります。
Yu-Pack rates are determined by size and weight.
I sent a present to my friend via Yu-Pack.
The package I ordered arrived by Yu-Pack.
For sending large packages, people often use Yu-Pack.