What makes Saisho no Mail by French Kiss notable?

'Saisho no Mail' reached significant commercial success, peaking at number 5 on the Oricon Singles Chart. The title track has been recognized for its engaging melody and relatable lyrics, contributing to the group's growing popularity and establishing them as a prominent act within the idol genre. Released on November 22, 2011, 'Saisho no Mail' is French Kiss's second single since their debut in 2010. At this point, the group was solidifying their presence in the J-pop scene, following their successful self-titled debut. This release showcased their evolving sound and thematic focus on love and relationships.