['seasonal allergic rhinitis']
['omalizumab', 'placebo']

        Inclusion criteria:

          -  A clinical history of Japanese cedar pollinosis defined by the following

               -  Took nasal corticosteroid plus one or more medications out of antihistamine
                  (second generation), leukotriene receptor antagonist, or prostaglandin D2
                  thromboxane A2 receptor antagonist in Japanese cedar pollen seasons in 2016 and
                  2017.

               -  Had inadequately controlled symptoms of Japanese cedar pollinosis lasting at
                  least one week in the Japanese cedar pollen season in 2017 despite the nasal
                  corticosteroid plus one or more medications out of anti-histamine (second
                  generation), leukotriene receptor antagonist, or prostaglandin D2/thromboxane A2
                  receptor antagonist (regardless of having perennial allergic rhinitis or not)

          -  Serum cedar pollen-specific Immunoglobulin E (IgE) levels of ≥ score of 3 by
             CAP/RAST-FEIA, ImmunoCAP or MAST at the screening epoch.

          -  Developing a symptom of Japanese cedar pollinosis during the period from first
             observational day in cedar pollen in Kanto area to initial drug administration (Visit
             101), as defined by the following

               -  Having any nasal or ocular symptom (≥ score of 1 in sneezing, rhinorrhea, nasal
                  congestion, itchy eye or watery eye) in at least 2 days or

               -  Having both any nasal symptom (≥ score of 1 in sneezing, rhinorrhea, nasal
                  congestion) and any eye symptom (≥ score of 1 in itchy eye or watery eye) in at
                  least one day, which is confirmed by patient e-diary (unless a symptom is clearly
                  consider to take place due to other than Japanese cedar pollinosis/allergic
                  rhinitis (e.g., upper respiratory tract infection, or common cold)).

          -  Body weight and serum total IgE level at screen epoch within the dosing table range;
             body weight of ≥ 20 to ≤ 150 kg and serum total IgE levels of ≥ 30 to ≤ 1500 IU/mL at
             a maximum.

        Exclusion Criteria:

          -  With an active rhinitis other than allergic rhinitis (e.g acute or chronic rhinitis,
             idiopathic rhinitis).

          -  With an active nose disease other than allergic rhinitis (e.g., acute or chronic
             rhinosinusitis or deflected septum) which is expected to affect the evaluation of
             efficacy of the study drug judged by the investigator.

          -  With elevated serum IgE levels for reasons other than allergy (e.g., parasite
             infections, hyperimmunoglobulin E syndrome, Wiskott-Aldrich Syndrome or clinical
             allergic bronchopulmonary aspergillosis).

          -  With a severe asthma treated with high dose inhaled corticosteroid (≥ 800 μg/day
             fluticasone propionate or an equivalent for aged ≥ 16 to <75 years, > 200 μg/day for
             aged ≥ 12 to <16 years).

          -  Who are receiving operative treatment for allergic rhinitis (e.g., electrocoagulation,
             laser surgery, 80% trichloroacetic acid chemo-surgery, inferior turbinectomy or
             posterior nasal neurectomy) within 1 years prior to the screening epoch.
      