Super Mario RPG: Legend of the Seven Stars

Super Mario RPG: Legend of the Seven Stars is the defeat of the Smithy Gang after an invasion across the Mushroom Kingdom and beyond.

Sudden Interruption
Princess Peach is suddenly kidnapped by Bowser while she was right outside Mario's House. Mario runs into action and heads to Bowser's Castle.

Mario makes quick work with Bowser, but everything is interrupted when a massive sword pierces through Bowser's Castle. The impact launches Mario right back into his house. He tries going back to Bowser's Castle, but the sword, Exor, announces the Smithy Gang's invasion and breaks the bridge heading to the castle.

Moving through Mushroom Pad, Mario saves a Toad from a pair of Hammer Bros. and reaches Peach's Castle to tell the Mushroom Kingdom Chancellor about this new gang. After telling, Mario heads outside and sees Mallow being robbed of his coin by Croco. Mallow joins Mario and they both chase after Croco in Bandit's Way.

Mack Tonight
After returning back to the Mushroom Kingdom, they find that it's taken over by Shy Guys led by Mack, a member of the Smithy Gang. Mario and Mallow head inside Peach's Castle and defeat Mack, getting the first Star Piece. Mallow suggests going to his grandpa, Frogfucius, for advice. At Tadpole Pond, Frogfucius tells Mallow that he's adopted.

Continuing on further, Mario and Mallow make it to Rose Town via Rose Pad. On the way there, they encounter Bowser gathering his troops. Reaching Rose Town, it's being terrorized by arrows that curses people to stop moving. Going inside for a breather, Mario meets Gaz playing with some toys. Gaz introduces his Geno toy, whose rocket knocks Mario unconscious.

Geno and the Star Road Ahead
At night, the Star Road suddenly brings the Geno toy to life and walks into the Forest Maze. Mario and Mallow follow him and make it to the culprit behind these cursed arrows: Bowyer. The gang joins Geno and they defeat Bowyer. The second Star Piece is collected and the gang heads to Moleville.

At Moleville, Mario and gang head inside the Coal Mines to find Dyna & Mite who are lost inside. While inside, they encounter Punchinello who starts to fight the gang. After defeating him, Punchinello drops a large Bob-omb, but the gang survive with the third Star Piece on hand. Going in further, they then find Dyna & Mite and return them to their parents.

Booster Moment
Mario then overhears from a group of Snifits trying to catch a beetle that their boss, Booster, is entertaining a princess that came from the sky. Working on a hunch, Mario's group heads to Booster Tower and happens to meet up with Bowser. It's confirmed Peach is up on the tower and Bowser, with possible regret, joins Mario to rescue Peach. Climbing upwards in Booster Tower and dealing with Booster himself, Mario's group finds Peach missing.

The group chases Booster towards Marrymore to stop the forced wedding between him and Peach. The group tries to leave, but the wedding cake becomes alive and tries to kill everyone, but Booster eats it in one gulp.

With Peach saved, everyone returns to Peach's Castle. Peach tricks the Chancellor and joins the group in finding the rest of the Star Pieces. This search leads them to Star Hill, where they just find the fourth Star Piece.

Smithy Gang Interruption
The group's next stop is Seaside Town. An elder there tells the group that he found a Star Piece falling into the sea. Diving under, the group finds a Sunken Ship and heads inside. fighting through the undead crew inside, they reach Jonathan Jones' room and fight for the fifth Star Piece.

At Seaside Town, Yaridovich, a Smithy Gang member, forces Mario to hand over the Star Piece by torturing the real citizens of Seaside Town. He heads off, but Blade comes in late, allowing Mario's gang enough time to then battle him for the Star Piece.

The gang then climbs Land's End, go through Belome again, and end up in Monstro Town for help. Monstermamma calls Sergeant Flutter, as she believes that a Star Piece could be in Nimbus Land. With help from the Paratroopas, Mario and the gang could climb a beanstalk taking them to Nimbus Land. On Nimbus Land, Valentina announces to the citizens that King Nimbus continues to be ill but introduces that the king's son, Prince Mallow, wants to marry her. In actuality, the son is a big bird called Dodo, but it convinces the people enough.

Using a clever disguise, Mario makes his way into Nimbus Castle thanks to the sculputor Garro. Valentina tries escaping Mario and friends, but they catch up eventually and defeat her along with her manipulation of the entire town. Mallow frees the royal parents and are reunited with one another, but Mallow continues with the group to head into Barrel Volcano which King Nimbus said might hold a Star Piece.

Inside the volcano, the Czar Dragon is fought and the sixth Star Piece is obtained. Surprise, the Star Piece is then nabbed by the Axem Rangers. Onboard the Blade, the gang fights the rangers and retrieves the Star Piece for real.

Between all that
At some point, Mario and the gang reach Yoshi's Island where Mario has to help Yoshi beat Boshi, who's only allowing one-on-one races and not group races. After beating Boshi in a leg race, Yoshi is now the leader of the Yoshis and everyone can now race in a group.

On Melody Bay, Mario helps Toadovsky compose a new piece for his song.

The group also fights Culex, a 2-dimensional ruler of all evil made from the power of evil from another dimension.

Heading to Bowser's Castle
Returning to Castle Nimbus, the Nimbus royalties suggest the last Star Piece to be in Bowser's Castle. With no bridge available to cross through, they allow Mario's group to use the royal bus. Walking through Bowser's Castle, the Smithy Gang has managed to hypnotize the Koopa Troop, which Kamek reveals after getting the hypnosis beat out of him. After fighting Boomer, the gang are led to the top floor of Bowser's Castle where they fight Exor.

Exor's defeat opens up a portal to another world where the Smithy Gang originates from. Moving through their base of operation, Factory, they encounter a wide variety of copies and members of the Smithy Gang, like Count Down, Cloaker, and Domino.

Their journey has finally led the gang to their leader, Smithy. In a multi-phase battle that brings everyone down to the Factory's basement, Smithy is fully destroyed with the last Star Piece fully obtained. With all of the Star Pieces on hand, the Star Road can now be completed. The star spirit inhabiting Geno leaves its host doll and the portal to Smithy's world is destroyed.

Epilogue
Mallow returns to his parents as the prince of Nimbus Land, Bowser and the rest of the Koopa Troop are fixing up the damage left to their castle, Jonathan Jones stares towards the cast ocean, Boshi leaves with Croco after losing a race against Yoshi, Toadofsky is hosting a concert, Valentina is forcing Booster to marry her, and Mario and Peach return back to the Mushroom Kingdom.

Luigi is hosting the grand parade celebrating Mario and his friends' victory. Geno, his true name being ♡♪!?, is also there to wave Mario and Peach off before returning back to the Star Road.

Timeline

 * Mario cannot speak the Yoshi language here and needs Yoshi to translate, placing it before future games in which Mario can understand the Yoshis.
 * Yoshi is still living on Yoshi’s Island, placing this game before future games in which Yoshi is living in the Mushroom Kingdom.
 * It’s heavily implied that this is Princess Peach’s first adventure, placing this game before Super Mario Bros. 2.
 * Birdo is born here.
 * Shy Guys are minions of Smithy here, not Bowser.
 * In this game some Shy Guys say “The mustachioed one is strong” in reference to Mario after Mack’s defeat, clearly surprised. This may imply that this is the Shy Guys’ first encounter with adult Mario.
 * Gaz has Mario toys, though they aren’t Mini-Mario Toys, perhaps suggesting that while the Mario Toy Company is open, Mario vs. Donkey Kong hasn’t happened yet.
 * This game is implied to be Kamek’s first encounter with adult Mario.