It was released by Avex Trax on December 5, 2007, and Rhythm Republic on April 9, 2008 as a double A-side with one of Hamasaki's tracks "Game" as the third and final single from her ninth studio album, Guilty (2008).

It was certified in two categories by the Recording Industry Association of Japan (RIAJ); as of June 2016, it has been downloaded over three million times, making this Hamasaki's highest selling single.

An accompanying music video was directed by Takahide Ishii, which displays Hamasaki waiting at a taxi stand, and another scene with her as a marionette.

[2] Bradley Stern from MuuMuse compared the composition and musical elements to the material from Hamasaki's 2002 album I Am..., and her 2003 EP Memorial Address.

[3] According to a staff reviewer at Japanese music magazine CD Journal, the song includes "quiet piano" riffs and "elegant string" arrangements.

[7] Then on April 9, 2008, "Together When..." was re-released by Rhythm Republic as a double A-side single, issued on a 12" inch vinyl, with one of Hamasaki's previous songs "Game" (which appeared on her sixth studio album My Story (2004)).

Bradley Stern, head writer from MuuMuse, awarded the song a maximum of ten points and labelled it one of the best tracks on Guilty.

"[2] A staff member at CD Journal enjoyed the song, labeling it a "beautiful performance" by Hamasaki; the reviewer also complimented the instrumentation and production, and how it "melted together comfortably".

As marionette dolls, they both walk past each other in a dark atmosphere, whilst the chorus has Hamasaki singing the song again at the bench.

A truck then drives past, which vibrates the puppet show's stage, causing the doll to fall on the ground and its strings become tangled.

It ends with the taxi driver, who finishes day dreaming about the marionettes dolls, opening the door for Hamasaki to enter.