back number will digitally release their new song "Kaitou" on May 24. 

"Kaitou" was written as the theme song for NTV's drama 'Koi wo Deep ni' starring Ishihara Satomi and Ayano Go. To coincide with the song's release, back number have launched their own Instagram account (@back_number_official). 

You can check out the teaser for "Kaitou" below!