I find interacting with KEGG using dbget via the Web extremely painful. So I'd go for a different approach.

Approach 1

Based on Is There Any Way To Retrieve Genes' Sequences In Fasta Format Using The Kegg Orthology Code? to a previous question, you could use the BioRuby Bio::KEGG::API to search and retrieve something like this:

#/usr/bin/ruby
require 'rubygems'
require 'bio'

serv = Bio::KEGG::API.new

# search for xac + hypothetical
xac = serv.bfind("T00084 hypothetical")
# get the IDS into an array
ids = xac.map { |gene| $1 if gene =~/^(.*?)\s+/ }
# retrieve fasta and print
ids.each { |id| puts serv.bget("-f -n 1 #{id}") }

This retrieves protein sequences; you'd need to adjust the parameters to bget for other options.

Approach 2

Download the fasta files from the NCBI (e.g. the *.faa files for protein sequence) and parse the header for the word "hypothetical" using one of the many tools available to parse fasta files.