The one-shot combined manga by Mitsuru Adachi (Touch, Rough, H2, Cross Game) and Rumiko Takahashi (Ranma 1/2, Maison Ikkoku, Inuyasha) has been scanlated and can be seen here:
It's the combined stories of their lives and how they got involved in manga as well as got to know each other. Written for the celebration of Shonen Sunday's magazine's 50th Anniversary.
Actually, what I really liked about it was learning more about the histories of two of my favourite mangakas. And it was interesting to see how much Takahashi respected Adachi-sensei, even though he thinks she did better than he did. (Didn't realise Adachi was 6 years older than Takahashi until this manga!) It really gives you a touching, nostalgic feeling of two old friends who've been through a lot together and are totally comfortable with each other. Plus that last page was great... very typical of the ironic humour that characterises their styles of storytelling.
Plus, Adachi = oldest person in shonen manga. Lol.
What do all the rest of you Adachi / Takahashi fans think about this?