The Spirit of Lake Toya possess the sword that Gintoki carries. Appearing in Chapter 150, he attempted to teach the Yorozuya an ultimate technique, the "Jumbolic Magnum," which sends the target flying into the sky with a single punch. A side-effect of the attack forces the victim to shed bodily fluids from his body. Unfortunately, none of the gang ever manage to learn the attack.  The spirit lives with his parents. His mother has an afro hairstyle with a white beard, and his father is constantly looking for a job. His father also has a sure kill technique, called the "Jack Nicolle," in which he shoots a beam from his bald spot. Toya also keeps a pet, and it sheds a large amount of curly hair. It is said that he was a fellow student to Taikobou, the main character of Hoshin Engi.  Lake Toya enjoys eating fried cuttlefish, as evidenced by the contents of his wastebasket. He claims the contents of his trash, strange smelling hardened tissue paper, are the remnants of the occasional cuttlefish feast, although Gintoki thinks otherwise. The spirit does keep a book collection of female figurines under his bed.  He is a parody of the character Zangetsu from manga Bleach.

Life isn't easy in feudal Japan... especially since the aliens landed and conquered everything! Oh sure, the new health care is great, but the public ban on the use of swords has left a lot of defeated samurai with a difficult decision to make concerning their future career paths! This is especially true if, as in the case of Gintoki Sakata, they're not particularly inclined towards holding a day job, which is why Gintoki's opted for the freelance route, taking any job that's offered to him as long as the financial remuneration sounds right. Unfortunately, in a brave new world filled with stray bug-eyed monsters, upwardly mobile Yakuza and overly ambitious E.T. entrepreneurs, those jobs usually don't pay as well as they should for the pain, suffering and indignities endured! 
(Source: Sentai Filmworks)

The samurai didn't stand a chance. First, the aliens invaded Japan. Next, they took all the jobs. And then they confiscated everyone's swords. So what does a hotheaded former samurai like Sakata "Gin" Gintoki do to make ends meet? Take any odd job that comes his way, even if it means losing his dignity.
 
(Source: Viz Media)
 
Included Bonus Chapters: 
Volume 1: Dandelion (One-shot). 
Volume 2: Shirokuro (One-shot). 
Volume 24: 13 (One-shot). 
Volume 38: Bankara-san Ga Tooru (One-shot). 
Volume 41: Special Lesson.

A special episode that was previewed at a screening at Jump Special Anime Festa 2014. 
The tagline for the anime reads, "It's time for all the Yorozuya members ...to wake up just one more time."
 
Note: On April 3, 2015, it was bundled with a limited edition of the manga's 58th volume.