If the anime hadn't included her sooner the arc with Bossun's past is the first time Rumi would have shown up in the series. I think the same goes for his mom too though she might have appeared briefly once before it. Anyways I just finished the anime version of the arc and still really enjoyed it.
On an unrelated note the newest Toriko chapter was so manly. One man vs ingredients in a wrestling ring complete with mic rants.
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http://myanimelist.net/animelist/swordz9