Usually marketers want a clear, simple, easy to understand message to promote or support a product. Japanese marketers however sometimes go for a challenging message that includes wordplay. If the customer is patient enough to play along, it can work.
Loose translation of the copy:
"In a world of increasing entanglements, troubles and having to care for others, sometimes you just want to eat some ice cream. Emptying a package of Soh (after eating Soh), can also clear your head (of worries). No Think, Soh Happy"
Here it is in Japanese:
「NO THINK そーハッピー！
NO THINK そーハッピー。」
Points of explanation:
The product name is Soh and uses the Chinese character for "refreshing".
The "so happy" or "Soh happy" in the copy naturally connects to the product name.
To my mind, it sounds like a cross between two old popular songs "Don't worry, be happy" and "We don't need no education".
ロッテ アイス 爽
Photo is a web capture for explanatory purposes, copyright belongs to the company.