Billboard Japan has recently reported that TWICE's Happy Happy already sold a total of 302,963 copies (including local and international sales as well as shipment) one week after its official release.

For local sales, according to recent updates, Oricon recorded 254,707 copies making it eligible for Platinum Certificate by Recording Industry Association of Japan (RIAJ). 

TWICE maintains their lead in the highest first week sales for physical Japanese singles by K-Pop girl groups on Oricon Chart:

1. TWICE's Candy Pop — 265,643
2. TWICE's Wake Me Up — 262,567
3. TWICE's Happy Happy — 254,707
4. IZ*ONE's Suki To Iwasetai — 221,640
5. IZ*ONE's Buenos Aires — 215,760
6. TWICE's One More Time — 200,722

Currently, TWICE holds 7 Platinum Certificates from RIAJ and fans hope that their 8th would come sooner as "Breakthrough" was released today. Fancy's Japanese version and Breakthrough have, in fact, dominated LINE Music Japan's chart as well as all the other tracks included in their back-to-back release.

Congratulations TWICE for another milestone!