No wonder this manga get low sales, the pace is too slow for Shounen manga standard. Most shounen manga wants more detail and fast paced action while this manga focus on romance than action and daily life of their journey.
Nevertheless, the action itself is too dull and not much action detail, even the hero's skill not shown much, only normal slash and exploiting his Undead status.
To me, this is actually fresh and sweet gag manga. But, the author is in the wrong magazine to publish.
But the manga sales itself doesn't guarantee the adaptation media like anime, except if the sales is too low