Let me clarify......
While this is true Japanese Language uses Hanzi like Chinese do, but the usage is not exactly like Indian-Pakistan, Danish-Swedish, Finnish-Swedish or Spanish-Portugal.
In all the latter case, words have the same form and coming from the same stem, so a Native Spanish Speaker will understand what a native Portugese is speaking without the latter speaking in Spanish. Same goes Danish will understand swedes speaking Swedish and Finnish will understand Swede and vice versa.
Japanese does not learn Chinese Character the way Chinese Learn Chinese Character. While we still understand most of the Kanji Japanese are using, Japanese based (Rather paired) Kanji with Hiragana. And they learn those Chinese Character via Hiragana.
Example : 明日
Chinese - Tomorrow
Japanese - Tomorrow
While the meaning is the same, the pronounciation is a lot different.
In Chinese, 明日 - Ming Yet (Nearest English pronounciation)
In Japanese, - A-SU-KA (Nearest English Pronounciation)
The different stem from the way Chinese and Japanese learn the same word, while Chinese learn the word DIRECTLY from the character, Japanese learn from Hiragana.
That is why even if Japanese Uses chinese character, the verbal communication cannot be established between a Japanese and a Chinese the same way an pakistani can talk to an Indian or a Portugese can talk to a Spainish
Then you also need to understand how often Kanji was used in a normal written conversation.
An standard Japanese passage will not use more than 20% of Chinese Character at one sentence and the word maybe different than it's Original Chinese meaning too
So for a Chinese to say he can read this o 50% or more of its value.
You are actaully saying an English Speaker can read any Spanish Text without any prior spanish knowledge. Which is impossible.
[reference: I Speak English, Chinese, Spanish, portugese, Swedish and my sister married to a Japanese.]