Shining Force II opens with a dark and stormy night. King Granseal and his minister attend to the Tower of the Ancients, under which is magically sealed a sleeping evil known as Zeon the Devil King. They observe the storm's coming at an unusual time of year, insinuating ominousness. Meanwhile in a shrine south of Granseal Castle, a thief named Slade unwittingly breaks the magic seal's power by stealing two jewels (of Light and Darkness), which eventually looses Zeon. At the Castle, with what appears and sounds like a tremendous bolt of lightning, a sealed door in the Tower of the Ancients is opened. The Minister of the King becomes alarmed.

Strange and ominous events ensue: The town of Granseal awakes the next morning to a sick King and an open Tower door. Sir Astral and the game's leader, Bowie, along with classmates Sarah (a priest/healer) and Chester (a centaur knight), investigate these events in the castle, starting with the opened tower door.

Greeting their arrival in the tower are devils named "Gizmos" springing forth to attack; their intentions yet-unknown. Upon defeat, the Gizmo that appears to be the leader flees to possess King Granseal. Sir Astral and Bowie and the developing Shining Force fly to the king, finding him possessed. Sir Astral exorcises the demon, which promptly flees.

The Minister, in place of King Granseal who is looking over a fainted Astral, then orders the slaying of the Gizmo by a platoon of Granseal-soldiers.

When the true danger of the opened door is realized, Bowie and friends have to fight against the invading armies of Zeon to find the Holy Sword and the stolen jewels so they may once again reseal the Devil King in Arc Valley.

[I couldn't really summarize it myself, so this is from another website so it may sound kinda cheesy, but it gives the general idea.]

Gameplay:

Shining Force II is a tactical role-playing game. The player assumes the role of the Shining Force leader, Bowie. When not in combat, the player can explore towns and other locales, talk with people, and set the members and equipment of the army. Some towns have a headquarters where the player can inspect and talk with his allies. While roaming through town or moving throughout the world, one can find both visible and hidden treasures and interact with certain objects.

Each ally unit is represented by a character with a background and personality. Some of these characters are hidden, requiring specific events to occur before they will join the force. Each ally unit also has a class, which defines the abilities for that unit. These abilities range from what type of weapons they can use to what kind of spells they can learn. Units can become stronger by fighting enemies and performing various actions which gives them tle="Experience point" style="color: rgb(11, 0, 128); background-image: none; ">expierence points (EXP), which allow them to gain tle="Level (computer and video games)" class="mw-redirect" style="color: rgb(11, 0, 128); background-image: none; ">levels. Once a unit reaches level 20, that character has the ability to advance to more powerful class through promotion. Some characters have two different classes they may be promoted to, one of which is only accessible using a special hidden item.

Battles take place on a square grid, and each unit occupies a single square. Battle is turn-based. Each turn, a character can move and perform one action: either attack, cast a spell, or use an item. Some commands, such as equipping or dropping an item during the turn, do not count as actions.

The battle is won if all enemies are defeated, or if the enemy commander is defeated. If Bowie is defeated in combat or withdraws, the battle is lost and the player is returned to the nearest town, where he can recover his allies and fight the same battle again.

I have only completed this game once, only because I always seem to find other things to do, but once in a while I go back to it and realize how much I love it all over again :3