How does the quote, "War makes people mean and ugly, and robs everyone's gentle hearts" relate to "My Brother, My Sister and I"?
Yoko makes this statement to alleviate Ko's guilt after Ko, overcome with remorse, recalls an incident during the flight from Nanam when she shouted at Yoko that she wished Yoko were dead. Yoko has sacrificed a lot to care for Ko during the months she has been hospitalized, most recently foregoing a pair of shoes for herself to buy calcium to help Ko get better. Even though Yoko, who back then had been "complaining all the time about (her) pain, deafness, (and) thirst," admits that she deserved harsh words, Ko "regretted it very, very much".
Yoko's observation echoes a central theme of the book - the dehumanizing effects of war. "Exhausted, hungry, begging, crippled" refugees who have lost everything struggle to survive in post-war Japan. Their desperation is clearly evidenced in the incident witnessed by Yoko when a destitute man fatally beats a young boy who had stolen his blanket. The Kawashima children themselves constantly guard against losing their dignity and humanity in the way they treat teach other, and succeed admirably. Yoko realizes this with appreciation, saying, "in spite of our cruel condition, Hideyo, Ko, and I were helping one another live day by day...I had absolutely nothing material, but I had a brother and a sister who gave me their love...they were teaching me the value of human life...I was proud of what we'd been doing" (Pt.2,Ch.1).