[Spectacular_Insanity]

Originally Posted by tennis1690

This is what I just read from Wikipedia on Kisuke Urahara:

Spoiler for Bleach - Kisuke Urahara History:

Kisuke Urahara is a former captain of the 12th Division of the Gotei 13. He is also the founder and the first president of the Shinigami Research Institute. Mayuri Kurotsuchi succeeded him in both positions.

It is known that Kisuke used himself as a test subject to attain the bankai of his zanpakutō in three days, rather than the usual hundreds of years of combat experience. Yoruichi supervised him while he did the training. Kisuke also commented that Ichigo has more potential than himself if Ichigo did the same training. This is true as Ichigo had in fact taken half a day less than Kisuke to learn his bankai.

At some point (about 100 years before the main Bleach storyline), Kisuke was sentenced to exile by Soul Society for creating an untraceable gigai which caused the spiritual power of the shinigami inside it to deteriorate and transformed them into humans, as well as the Orb of Distortion.[3] Yoruichi helped him escape and, for reasons yet unknown, ran away with him as well. He also seems to be an acquaintance of Isshin Kurosaki, Ichigo Kurosaki's father, and of Ryūken Ishida, Uryu Ishida's father.

I think it is possible that this gigai he created was for Isshin Kurosaki, and this is the reason how Isshin managed to stay so long in the living world when he was a shinigami captain. This would explain how Masaki was able to physically see him (Masaki had no spiritual power as she was not able to see Grand Fisher when he attacked her and there's been no hint she ever had it). Of course, Isshin and Masaki met and eventually got married and had 3 kids. Isshin was so happy and in love w/ Masaki that he decided to quit his shinigami duties and remain in the living world forever.

Fast forward to the second attack of Grand Fisher on Ichigo (inhabited by Kon that is), and we see Isshin has regained some of his shinigami powers (he is seen with his shinagami captain robe after he has decided to finally abandon his gigai). I believe that sometime after Masaki died, Isshin started regaining his powers mainly because he felt he needed to in order to find and defeat the hollow that killed her wife (it may have taken very long for him to regain some of his power because he may have been a very strong captain, and this would also explain where Ichigo got all his power from and don't forget the speed at which Ichigo keeps improving).

Tell me what you think!

Well, it would certainly make sense. At least the part about the gigai. I don't remember much about Ichigo's mother, but overall I would say it's extremely plausable.