[2] As this is her only single to receive any kind of certification to date, this makes "Itsu no Hi mo" her most successful.

The protagonist of the song, on the verge of a break-up, expresses how happy she feels right now, and wishes that every day she can look back and remember her relationship how it is today.

She created the theme of the song after realizing that at that point in her life, she treasures that person more than she ever will again, so she should save these memories.

[12] Her song My Baby from her debut album Free had previously been used for this tie-up in the 2008-2009 ski season.

[1] After charting lowly for five weeks, "Itsu no Hi mo" reached at #2 on the Billboard Japan Hot 100 due to heavy rotation on radio stations.

The song debuted at #9 on Oricon's daily charts, her highest position in her career to date (though Pop beat this record, reaching #3).

[15] The song eventually sold 9,000 copies, outselling her previous single "Anata no Koibito ni Naritai no Desu," but not "Tsutaetai Koto/I Wanna See You.

"[15] In April 2010 the song was certified by the RIAJ for gold (100,000 copies) as a full-length cellphone download.