On Mon, 29 Apr 1996, Lizsue wrote:

  ...The funeral, standing with a small knot of Hibikis and Kuonjis 
and one madly sobbing Tofu as the caskets, mercifully closed, were 
lowered into the earth. The birds, oblivious to everything but the 
warm sun and fine day, had sang their hearts out as the first 
shovelfuls of earth was tossed into the gaping holes. She had just 
stood there, wishing it were over and yet afraid to go, because that 
would mean they would really be gone...

Now how can Tofu sob so much if he doesn't have a chest cavity?  

We know that Dr. Ono Tofuu has but one surviving relative...his mother.

I would presume that SHE is the 'madly sobbing Tofuu' referred to in the 
story. :)