Since around 2013-11-06 14:00 PST, the Twitter API search is regarding “gooブログ” (without quotes, no space) as two words, and hitting numerous entries.
It was treated correctly as one word before that time.
The search at: https://twitter.com/search-advanced takes “gooブログ” (without quotes, no space) as one word.
I see only change made for Twitter API on the day is “HTTP 1.0 will be deprecated on November 6, 2013 for User & Site Streams”, so it may be the case it is affecting on this issue.
Could you check if it is the case?