The background music being played on loop in AKIHIDE “SOLO” LIVE 2019 NAKED MOON2 -Hoshi Oi no Shoujo- website is titled Hoshikai no Shounen
Preview snippet of Hoshikai no Shounen is about 33 seconds
So now alongside with Ajisai no Umi that can be heard being played on loop via AKIHIDE Premium Night Show 2019 -Gekko no Ryodan- website , Hoshikai no Shounen is the 3rd new AKIHIDE song that's now currently not included in a solo release of his
That alongside with Namida no Umi o Koete which AKIHIDE played/debuted for the 1st time during AKIHIDE Premium Night Show 2019 -Gekko no Ryodan-
Wouldn't surprise me if AKIHIDE will perform all 3 songs during AKIHIDE “SOLO” LIVE 2019 NAKED MOON2 -Hoshi Oi no Shoujo-