I bought volume 1 last year and didn't really like it, but this year I saw volume 2 on sale in Book-Off for about 60p. Also, this series has lots of dialogue-free pages that read quickly. So I bought it.
I liked this volume better. There's no Macho Military bullshit. Similarly, we're spared the Gritty Suicide Squad mission briefings that our heroes are now undertaking, since at least they've now reached the island and needn't listen to soldiers yelling about it. In other words, we've lost the boring stuff from volume 1. Reonne (i.e. Leon) and Doudou are hanging out in 23rd century post-apocalyptic Japan, which is devoid of pureblood humans but has plenty of exotic mutants. Ippatsu is still drawing epic pages of urban devastation, collapsing skyscrapers, etc. It's pretty amazing to look at. Leon and Doudou meet weird locals. They help an ostrich girl (Tsumugi) dig out her scary monster tiger friend and save his life, which was the most likeable character beat yet in this series. It wins them Tsumugi's friendship, unsurprisingly. They survive serious danger.
Ippatsu's character design for Doudou is still a cartoonish caricature of a black person that looks liable to give offence... or is it? On closer examination, it's not that bad. The actual pencils are good and convey lots of character. The problem is the shading, which gives the dark-faced Doudou white hair, lips and mouth, making his face look like weird pseudo-blackface make-up.
It's more surprising, human and engaging than volume 1. Tsumugi is charming, but scary. It looks amazing. The manga's made it up to "okay" and apparently an anime TV series adaptation has been announced. (No indication yet of a broadcast date, though.) I nearly bought volume 3 too, but there's always next year's Japan visit...