One thing that I've found with Mushishi is that it often touches on more than just one theme at a time. To varying degrees, social, existential, and fear philosophies are all explored in one way or another over the course of the series. This episode exemplified that rather well, glancing at social stigmata, selfless support, and overcoming ignorance to understand someone. But most interesting to me was the idea of addiction.
|Also, you're two for two with the cute robe girls now, Mushishi.|
Sui has developed an eye disease where she is extremely sensitive to the slightest amounts of light (due to a mushi in her eyes). As a result, she is sent to another family to live in their blackout shed. In the darkness, Sui discovers how to close her "second eyelid" (the idea is that when we close our eyes, we're still seeing the insides of our eyelids - this is the ability to actually "turn off" one's eyes). While they're closed, Sui becomes able to see the river of Kouki that appeared in episode 1 - which is essentially the river of life. Supposedly, this river is incredibly pleasing to look at, with one character suggesting he wanted to stay and observe it forever after spending only a few seconds of seeing it. That's the "drug" of this addiction.
Ginko, who can also close his second eyelid, warns Sui to not look directly at the river or try to get closer to it (apparently, it serves as a sort telepathic relay, allowing the two to communicate despite being physically distant). In other words, he warns her against abusing it. So, Sui keeps looking, but safely.
Then in the physical world, Biki (Sui's only friend) catches her disease. Ridden by guilt, Sui goes directly to the river - an overdose, in a sense. Both her eyes are rendered useless as a result, cementing her life in darkness. With Ginko's appearance in the physical world, however, things turn around. He cures Biki, preventing his "addiction" from starting, then turns to Sui. After removing the mushi from her eyes, he then injects a special mushi into his own glass eye and gives it to her, granting Sui sight again. Afterwards, it is noted she will likely never be drawn to look at the river again.
|And who could blame her, after this?|
The root cause is dealt with upon the removal of the mushi, the after effects are - imperfectly (it's only a single, artificial eye) - cured with the glass eyeball, and the addiction is supposedly gone forever. Given Mushishi's medical side, such a procedural string of events (and one that ends so well, at that) is hardly surprising, but it's intriguing to think of the life as drug, best used in significant moderation with severe ramifications if abused. That, and I get a kick out of viewing Ginko as a rehabilitated addict.
P.S. If you're interested, the series is free to watch on Funimation's website and Youtube channel.