It's available on mangago in it's entirety, but it sends you to the creepiest ads that are loaded the moment you click on a chapter. That is, the link it's open on in the web address changes to that of that ad by the time you're already reading the first page. You can see it redirect almost instantly when you click, or if you copy the URL that contains the chapter. But it is complete including a short extra: http://www.mangago.me/read-manga/hana_wa_saku_ka/