Masami Eiri (英利 政美, Eiri Masami), is the key designer of Protocol 7. While working for Tachibana Laboratories, he illicitly included code enabling him to control the whole protocol at will and "embedded" his own consciousness in said protocol. Consequently, he was fired by Tachibana Labs, and was soon found dead on a railway, having seemingly committed suicide. It is his belief that the only way for humans to evolve further is to absolve themselves from their physical limitations and live as digital entities.
In Layer 12, Eiri becomes infuriated by Lain's resistance and attempts to manifest himself physically, becoming an abominable floating creature sprouting a prehensile tongue and bizarre fleshy growths all about his misshapen body. Fortunately, before Eiri is able to harm Lain or Alice, Lain smashes him into a bloody pulp by telekinetically throwing all of her hardware and equipment at him.
After Lain resets both The Wired and reality (it's unclear if they are in fact the same), he is seen grumbling on his way to work for Tachibana, idly threatening to quit.