https://www.rpginsanity.com/forum/warlo ... -possible/
I'm currently just starting the game, in fact, I'm just in the beginning section of the game where I'm going to the secret passage and meeting Nobushige and again Masamune.
What I notice just at the start of the game are Masamume dialogues.
Like what Siegfred said in his post, Masamune dialogues makes you question or wondered what is the canon gender. Like Masamune dialogue in the secret passage that "character" getting cuter lately. Which is somehow implied that the canon gender is possible Female but who know, maybe Masamune is umm y'know but hey, it's based on old Japan. Like Yaoi is not possibly happened during those Era hahaha.
Also if you check out the main site of the game in EXE-CREATE website.
http://www.exe-create.co.jp/kei/sen_kei/sen_pc.htm
You can see that main cover is Hiro, so this is one possible factor making Hiro the canon one.
Now, about the sequels.
Warlord Revivals does have 2 sequels, with still same name. Like no no. 2 or extra title.
Just "Samurai of Legend", All three sharing both names.
1 is playable via English ver (with something you need to do to play it in full)
2 and 3 is still Japanese exclusive for old phones. (not new phones, old phones like literally era of Flip phones.)
Series is made after the release of Asdivine SaGa which is made in 2008 so those games was possible made in the same year as Asdivine SaGa or after 1 year which is 2009 until 2011 maybe since Across Age was made after the first one and before the 2 sequels.
Three games is all about Dystopia attacking Hinomoto which is possible Japan (since when i opened those site, they're auto translated by the Google translate in the site itself so.. that's what happen haha

All game is about Dystopia attacking Japan until they beaten up once and for all by another Tachibana and a new Hero in the 3 third game.
To give more detailed info about it, here's the summarized version based on my bad grammar.
1 is about revived warlords/samurais who is revived by Dystopia to make them fight they own fellow samurais to conquer Japan but they Instead is they protect their own country.
2 is about a new battle for peace. Dystopia try to invade and broke the peace of Japan once again. Some Samurais stand up again to fight the upcoming Dystopia.
3 is about Yakumo Tachibana and Minamoto no Yoshitsune was about to protect the Japan from the third "Third" invasion of Dystopia.
There are some interesting characters in sequels like Jeanne d'Arc in second game and Nostradamus in third game.
Also one of the main antagonist, which is Gailles is part of the whole 3 game as Dystopian Antagonist.
'
For more info, check the site itself.
(1st game) http://www.exe-create.co.jp/kei/sen_kei/sen_pc.htm / http://www.exe-create.co.jp/kei/sen_kei/hibiki_pc.htm
(second game) http://www.exe-create.co.jp/kei/baku_kei/baku_top.html / http://www.exe-create.co.jp/kei/baku_kei/baku_top.html
(third game) http://www.exe-create.co.jp/kei/genpei_kei/gen_top.html / http://www.exe-create.co.jp/kei/genpei_kei/gen_top.html
I think i forgot something to add and i don't remember about it so if there something missing, kindly share it.