Boy band SHINee is gearing up for a full group comeback following two years of military hiatuses.

On Tuesday, Taemin of SHINee was discharged from his military duty as the last member of the quartet to complete the compulsory service.

Taemin's discharge comes a year and 11 months after he enlisted in May 2021. Beginning his service in the Army band, Taemin was transferred from active duty in January last year after his symptoms of depression and anxiety worsened. The singer served out his remaining time in the reserve forces.

Taemin on Tuesday posted a letter to fans online, thanking those who supported him through his service.

“I’ve missed (you) so much that words are not enough and (I) believe that you guys trusted and waited for me with the same heart … this thought has strengthened me and made me more mature,” he wrote, promising he would work to make them happier.

The other bandmates, Onew, Key and Minho, finished their active duty in 2020, with Onew and Key serving in the Army and Minho in the Marine Corps. The three members have since been carrying out solo activities.

Marking the 15th anniversary of its debut in May, SHINee has been heralding its comeback over the past few months.

In December, Minho -- also an actor -- said during an interview for Netflix's "The Fabulous" that "SHINee is preparing an album to celebrate its 15th anniversary." Onew divulged even more during his solo comeback performance on Mnet's M Countdown in March, saying, "(The album) is about our 15th anniversary. It's coming out this year and we will show you more than what you expect from us." Key also said in a recent fan meeting that the group has started recording for the new album.

After all these hints from members, SHINee is indeed expected to drop an album -- likely its eighth LP -- around the time of its anniversary on May 25. The album will mark the first full group comeback for the quartet since it released its repackaged seventh LP, "Atlantis," in April 2021, just before Taemin's enlistment.

Debuting in 2008 under SM Entertainment, SHINee has since released hits, such as "Relay," "Ring Ding Dong," "Sherlock," "View" and "1 of 1," through which it has carved out its own genre of fantastical and trendy sounds.

Fifteen years into the group's career, SHINee is considered the ideal, long-lasting K-pop group in this industry where many groups come and go.

With its seventh LP, "Don't Call Me," which was released in February 2021, the group set a new career high, with the album racking up the team's highest sales ever and the music video for the namesake title song reaching their first 10 million views.

The two sets of military hiatuses never played out negatively for the group. While the elder three members were away, Taemin spent the time spreading his wings as a solo musician, dropping solo albums, including "Never Gonna Dance Again : Act 2" and "Advice," and holding concerts in both Korea and Japan.

Then, during Taemin's absence, Onew, Key and Minho also developed each of their solo careers. Most recently, Key dropped his second reissued LP, "Killer" and Onew, his first LP, "Circle." Minho dropped his first solo album, "Chase," while continuing a career in acting.

Meanwhile, Taemin is set to hold a fan meeting "Re : Act" on April 22-23 in Seoul, reuniting with fans in person after three years and four months since his last solo fan-meeting held in December 2019.