Upon starting a new game it shows an aerial view of the world then three text bubbles.
1st Text bubble
あてどなくロンバルトの地を旅するさすらい人ありき。
// A traveler aimlessly wanders the land of Lonbalt.
旅人の名こそハイゼンガルド。
// The traveler's name is Heisengard.
その者、比類無き秘めたる力を持ちながら使途を得ず。
// He hides a power unmatched, but [doesn't? can't?] use it.
ロンウォールの神降り立ち、かの者に神託を下す。
// The God Lonwahl descends and bestows a prophecy upon him.

2nd Text bubble
曰く、「同志を糾合し、世の和を脅かす邪悪なる魔王を滅すべし」
// It stated: "You must gather comrades and defeat an evil Demon Lord who would destroy the peace of the Earth. [tl note: i guess these guys don't actually live on earth. replace appropriately!]
光明得しハイゼンガルド、勇者としての一歩をユークレナにて踏み出す。
// Heisengard, who now held the future in his hands, took his first step as a hero in Euchrana.
3rd text bubble
『ロンウォール・サーガ序章』より
// From the Lonwahl Saga Prologue

The game loads to a battle.  There is a party of 5 on one side and one dark looking guy standing at what looks to be a throne.
The next lines are a conversation that takes place as they trade blows.  The first line of a pair is the person the second is what the person says.  One of the 5 dosn't talk.

ハイゼンガルド Seemingly the leader of the 5
     「魔王バルトガイスト、覚悟！！」
// Heisengard
//		"Demon Lord Bartogeist, prepare yourself!!"

魔王  Seemingly the bad guy
     「ここまで攻め入るとは‥‥うぬはただの人間ではないな！？」
// Demon Lord
//		"To come this far... You must not be a mere mortal!?

イニム
     「くっくっ。神より直に神託を受けし者。ただの人間であろうはずがなかろう」
// Ineme
//		"Heh, he received a prophecy from God Himself. Do you think he is a mere mortal?"

バルロー
     「そう言うことだよ」
// Balrow
//		"That's right."

フェイメア
     「神に仇成す者、もはやこれまでと知りなさいっ！」
// Feymer
//		"Affront to the heavens, know this!!"

魔王
     「よかろう！‥‥儂も魔王と呼ばれし者。うぬらごときに倒されはせぬわ。来るがいい！」
//	Demon Lord
//		"Very well... I am called the Demon Lord. I shan't be defeated by the likes of you. Come at me!"

魔王
     「笑止！」
//	Demon Lord
//		"Pitiful!"

魔王
     「ば、ばかな‥‥こ、この儂が人間ごときに」
//	Demon Lord
//		"Ho.. How is this... How can humans lay a hand on me...?"
フェイメア
     「と‥‥とどめをっ！」
//	Feymer
//		"Now's our chance!"

ハイゼンガルド
     「んっ！！これで終わりだ！！」
//	Heisengard
//		"It's time to end this!"

魔王
     「ううっ！！この力は！？‥‥神託だとぉ？‥‥うがあぁ！」
     「‥‥もしや‥‥もしや、うぬはぁ‥‥‥‥‥‥‥‥」
//	"Demon Lord"
//		"Uggh! This power... the prophecy.. Ugaah!!"
//		"...You... are you......"
The battle ends.

The game goes back to an aerial view of the world and then four text bubbles.
1
民を率い魔界を席巻せし大勇者ハイゼンガルド。
同志たる四勇者を従え、居城にて魔王を倒す。
人界魔界の統一は成れり。
// The hero Heisengard led his people to the magical realm and conquered it.
// With four heroes following him, they defeated the Demon Lord himself.
// The human and magical realms were joined.

2
五大勇者、勇者王となりてロンウォールを統治す。
ここよりロンバルトに調和と平和の時、訪れん。
// The five heroes became kings and ruled over Lonwahl.
// Never had Lonbalt experienced greater peace.
// [not super clear on the names or which is what but i hope you get the gist!]
3
『ロンウォール・サーガ終章』より
// From the "Lonwahl Saga Epilogue"
4
そして、魔王城陥落から１０数年の歳月が流れた‥‥
// And some years after the fall of the Demon Lord...